An Overview of Regular Dialysis Treatment in Japan (As of 31 December 2010)

Authors


  • Published in J Jpn Soc Dial Ther 2012;45(1):1–47 (in Japanese). Reprinted with permission from the Journal of the Japanese Society for Dialysis Therapy.

Dr Yoshiharu Tsubakihara, Professor, Department of Comprehensive Kidney Disease Research, Osaka University Graduate School of Medicine, 2-2, Yamadaoka, Suita city, Osaka 565-0871, Japan. Email: cyq06075@nifty.ne.jp

Abstract

A nationwide statistical survey of 4226 dialysis facilities was conducted at the end of 2010, and 4166 facilities (98.6%) responded. The number of new patients introduced into dialysis was 37 512 in 2010. This number has decreased for two consecutive years since it peaked in 2008. The number of patients who died in 2010 was 28 882, which has been increasing every year. The number of patients undergoing dialysis at the end of 2010 was 298 252, which is an increase of 7591 (2.6%) compared with that at the end of 2009. The number of dialysis patients per million at the end of 2010 was 2329.1. The crude death rate of dialysis patients in 2010 was 9.8%, and has been gradually increasing. The mean age of the new patients introduced into dialysis was 67.8 years and the mean age of the entire dialysis patient population was 66.2 years. Regarding the primary disease of the new patients introduced into dialysis, the percentage of patients with diabetic nephropathy was 43.6%, which is a slight decrease from that in the previous year (44.5%). Patients with diabetic nephropathy as the primary disease accounted for 35.9% of the entire dialysis patient population, which approaches the percentage of patients with chronic glomerulonephritis as the primary disease (36.2%). The percentage of patients who had undergone carpal tunnel release surgery (CTx) was 4.3%, which is a slight decrease from that at the end of 1999 (5.5%). The decrease in the percentage of patients who had undergone CTx was significant among the patients with dialysis durations of 20–24 years (1999, 48.0%; 2010, 23.2%). A total weekly Kt/V attributable to peritoneal dialysis and their residual functional kidney was 1.7 or higher for 59.4% of patients who underwent peritoneal dialysis.

The Japanese Society for Dialysis Therapy (JSDT) has been conducting a statistical survey of dialysis facilities across the country annually since 1968. Initially, only the numbers of dialysis patients and beds for dialysis were investigated in the annual surveys of dialysis facilities. However, data on all dialysis patients treated in facilities that participated in the surveys have been registered in an electronic database since 1983 (1).

The classification of the causes of death was changed in the 2010 survey. The classification was first changed in the 2003 survey and used until 2009 (2). The purpose of the change in the classification in the 2003 survey was to become compliant with the tenth revision of the International Classification of Diseases (ICD-10). However, some criticized the ICD-10 code classification for not necessarily capturing the actual conditions of dialysis patients in Japan. Therefore, we modified part of the conventionally used classification to more appropriately reflect the actual conditions of dialysis patients in Japan while retaining consistency with the conventional classification in the 2003 survey.

In the 2010 survey, the following items were investigated in addition to the basic survey items.

First, items associated with dialysis amyloidosis were investigated after the first 1999 survey (3). Dialyzers capable of efficiently eliminating β2-microglobulin (β2m), a substance causing dialysis amyloidosis, are widely used today (4). However, the prevalence of dialysis amyloidosis had not been examined since the 1999 survey. In the 2010 survey, the history of undergoing carpal tunnel release surgery (CTx) was investigated as a surrogate index of dialysis amyloidosis.

Second, dementia, activities of daily living (ADL), and the place of residence of individual patients were investigated as was done in the 2009 survey. The surveys in two consecutive years revealed changes in these items over one year, enabling the analysis of the factors associated with these changes. The surveys on the above items in two consecutive years are expected to yield data that can be used to establish guidelines for hemodialysis therapy, which are currently being prepared by JSDT.

Third, the current status of patients who underwent peritoneal dialysis (PD) was investigated as in the 2009 survey. In the facility survey, the number of patients who underwent PD and another blood purification therapy (PD + another therapy patients) was investigated. A detailed investigation of patients who underwent PD was carried out only in the patient survey using electronic media (specifically, items associated with PD were not investigated in the patient survey using paper media).

Fourth, the quality of dialysate has been investigated continuously since the 2006 survey. From 2010, facilities that maintain a certain quality of dialysate can request additional points in the medical insurance system in Japan. This is due to the fact that high quality dialysate is associated with a good prognosis for dialysis patients, as demonstrated from analyses of previous surveys.

In this report, we summarize data obtained from the 2010 survey on the following items:

  • 1Basic demographics
  • 2Current status of dialysate quality control
  • 3History of undergoing CTx
  • 4Items associated with dementia
  • 5Items associated with PD

The annual rapid report of survey is published on the JSDT homepage (http://www.jsdt.or.jp/) as “The Illustrated, Current Status of Chronic Dialysis in Japan” (hereafter, the Report) in order to widely distribute survey findings among JSDT members. However, a CD-ROM that contains detailed data from each annual survey (“Current Status of Chronic Dialysis in Japan, (the CD-ROM Report”, hereafter referred to as the CD-ROM) had been distributed to a limited number of members, such as facility members, supporting members, and the board of trustees. But from June 2012, each member can use the CD-ROM to search for necessary information also on the JSDT homepage.

Moreover, in 2010 we received many proposals on open recruitment research projects that were started 3 years before. The results of accepted open recruitment research projects and research carried out by the Committee have been published in journals. Findings from this survey are also used as the basis for establishing various guidelines, which are being prepared by JSDT and which contribute to the improvement of dialysis care in Japan.

PATIENTS AND METHODS

Method of survey

This survey is conducted every year by sending questionnaires to target dialysis facilities. A total of 4226 facilities surveyed were either member facilities of JSDT, nonmember facilities offering chronic hemodialysis (HD), or nonmember facilities offering PD but not HD as of December 31, 2010. The number of facilities participating in this survey increased by 30 (0.7%) from the previous year (4196 facilities) (5).

The questionnaires were mainly sent and collected by postal mail; some were also faxed. Electronic media (universal serial bus or USB memory drives) were sent to facilities that requested them in advance instead of paper questionnaires. Microsoft Excel worksheets stored on the USB memory drives were used to collect survey results.

In this survey, two sets of questionnaires were used. The facility survey investigated items related to dialysis facilities such as the number of patients, the number of staff members, and the number of bedside consoles used at individual facilities (using the questionnaire referred to as “Sheet I”). The other survey was the patient survey, which captured the epidemiological background, treatment conditions, and outcome of treatment of individual dialysis patients (using the questionnaires referred to as “Sheets II, III, and IV”).

The acceptance of responses ended at the end of January 2011. The acceptance of additional responses received after this deadline finally ended on 20 April 2011 for the preparation of the Report and on 20 September 2011 for the preparation of the CD-ROM.

For the CD-ROM, the number of facilities that sent their responses to the facility survey (Sheet I) was 4166 (98.6%), and the number of facilities that responded to both the facility and patient surveys (Sheets I–IV) was 4066 (96.2%). Moreover, the number of facilities that sent their responses using electronic media was 3545 (83.9%). The number of facilities that responded to the questionnaires using electronic media was higher than that in the 2009 survey (3352 facilities, 81.1%). This increase in the number of facilities using electronic media contributes to the accurate and simple analysis of survey data.

This report is based on the data tabulated for the CD-ROM.

Survey items

The following items were investigated in the 2010 survey.

Facility survey

The following items were also investigated in the 2009 survey (5).

  • • Name and address of facilities
  • • Year and month when the facility started dialysis treatment
  • • Total number of patients who can simultaneously receive dialysis
  • • Maximum capacity
  • • Number of bedside consoles
  • • Number of workers engaged in dialysis treatment (e.g. doctors, nurses, clinical engineers, nutritionists, caseworkers)
  • • Number of patients who underwent dialysis at the end of 2010 (daytime dialysis, nighttime dialysis, home HD, PD)
  • • Number of patients who did not undergo PD despite having a peritoneal catheter for PD (including those who underwent only peritoneal lavage) among those who underwent daytime dialysis, nighttime dialysis, or home HD (hereafter, denoted as non-PD + catheter patients)
  • • Number of patients who underwent both PD and another blood purification therapy by extracorporeal circulation such as HD and hemodiafiltration (HDF) (hereafter, denoted as PD + another therapy patients)
  • • Number of patients who underwent dialysis in 2010 and were hospitalized
  • • Number of new patients who were started on dialysis in 2010
  • • Number of new patients who were started on PD during 2010 but introduced to other blood purification therapies in 2010 as a fraction of all patients started on dialysis in 2010 (hereafter, denoted as PD dropout patients)
  • • Number of bedside consoles equipped with an endotoxin retentive filter (ETRF)
  • • Use or nonuse of ETRFs for collecting dialysate samples
  • • Site from which dialysate was sampled for dialysate test
  • • Frequency of measurement of endotoxin concentration in dialysate
  • • Endotoxin concentration in dialysate
  • • Frequency of measurement of bacterial count in dialysate
  • • Volume of sample for measurement of bacterial count in dialysate
  • • Medium used for cultivation of bacteria in dialysate
  • • Bacterial count in dialysate

Patient survey

The following are the basic survey items that have been continuously collected since 1983.

  • • Anonymous name of patient
  • • Gender
  • • Date of birth
  • • Year and month of starting dialysis
  • • Year and month of transfer to another hospital
  • • Primary disease
  • • Prefecture where the patient lives
  • • Treatment method
  • • Month of transfer (Code of facility to which the patient is transferred)
  • • Month and cause of death
  • • Year and month of changing treatment and change in code

The following items were collected in addition to the basic survey items using both the paper and electronic media. There were no new survey items.

  • • Current status of combined use of PD and another blood purification therapy such as HD and HDF (hereafter, denoted as current status of combined use of PD and another therapy)
  • • Number of years on ongoing PD (PD duration)
  • • Frequency of dialysis (e.g. HD) per week
  • • Duration of one session of dialysis (e.g. HD) (dialysis duration)
  • • Type of dialyzer membrane used
  • • Area of dialyzer membrane
  • • Height
  • • Predialysis and postdialysis weights
  • • Predialysis and postdialysis blood urea nitrogen (BUN) levels
  • • Predialysis and postdialysis serum creatinine levels
  • • Predialysis serum calcium level
  • • Predialysis serum phosphorus level
  • • Predialysis serum albumin level
  • • Predialysis serum C-reactive protein (CRP) level
  • • Predialysis blood hemoglobin level
  • • Measurement method for serum parathyroid hormone (PTH) level
  • • Serum PTH level
  • • Predialysis and postdialysis serum β2m levels
  • • History of undergoing CTx
  • • Complications of dementia
  • • Activities of daily living (ADL)
  • • Place of residence
  • • History of cardiac infarction
  • • History of cerebral hemorrhage
  • • History of cerebral infarction
  • • History of quadruple amputation
  • • History of femoral neck fracture

The following are the items collected through the electronic media in addition to the basic survey items in the facility survey. These survey items target PD patients only. New survey items are asterisked.

  • • Four-hour creatinine dialysate/plasma ratio in peritoneal equilibrium test (PET) (PET Cr D/P ratio)
  • • Type of dialysate used for PD (Type of PD solution)
  • • Volume of PD solution used per day (Volume of PD solution)
  • • Daily urine output
  • • Kt/V for residual kidney* (residual-kidney Kt/V)
  • • Kt/V for PD* (PD Kt/V)
  • • Number of times peritonitis occurred per year
  • • Complications with encapsulating peritoneal sclerosis (EPS) and its history*

Calculation of survival rate

The cumulative survival rate after initiation of dialysis was actuarially calculated (6).

RESULTS AND DISCUSSION

Basic demographics

Number of patients

Table 1 shows a summary of the dynamics of the dialysis patient population in Japan at the end of 2010 obtained in this survey. As mentioned above, the number of facilities that responded to the questionnaire (the facility survey) in the 2010 survey was 4166. Data on the number of years on dialysis (dialysis duration) and the longest duration on dialysis were obtained from the patient survey. All the other results were obtained from the facility survey.

Table 1. Current status of chronic dialysis therapy in Japan (as of 31 December 2010)
  1. Number of peritoneal dialysis (PD) + another therapy patients: Number of patients who underwent both PD and another blood purification therapy such as hemodialysis (HD), hemodiafiltration (HDF), hemoadsorption, or hemofiltration (HF) (excluding those who underwent only peritoneal lavage). Number of non-PD + catheter patients: Number of patients who did not undergo PD despite having a peritoneal catheter but underwent another blood purification therapy such as HD, HDF, hemoadsorption, or HF (including those who underwent only peritoneal lavage). §Number of PD dropout patients: Number of new patients who were started on PD in 2010 but introduced to another blood purification therapy within 2010.

Number of facilities4 166Increase of 33 (0.8%)  
EquipmentNumber of bedside consoles118 622Increase of 3643 (3.2%)  
CapacitySimultaneous dialysis (people)116 819Increase of 3332 (2.9%)  
Maximum accommodation capacity (people)395 724Increase of 12 194 (3.2%)  
Chronic dialysis patients298 252Increase of 7591 (2.6%)  
Patients per million2 329.1Increase of 49.6 (2.2%)  
Daytime dialysis246 146(82.5%)  
Nighttime dialysis42 052(14.1%)  
Home dialysis277(0.1%)  
Peritoneal dialysis9 773(3.3%)  
Number of PD + another therapy patients1 983   
Number of non-PD + catheter patients406   
Number of PD dropout patients§137   
Number of patients newly introduced to dialysis37 512Decrease of 54 (0.1%)  
Number of deceased patients28 882Increase of 1236 (4.5%)  
(The above data were obtained from the facility survey)
Duration of dialysis MaleFemaleUnknownTotal
0 < 5 90 81648 5550139 371 (48.2%)
≥5 < 10 45 55627 764073 320 (25.3%)
≥10 < 15 21 48514 853036 338 (12.6%)
≥15 < 20 10 5718 281018 852 (6.5%)
≥20 < 25 5 5644 771010 335 (3.6%)
≥25 6 1285 105011 233 (3.9%)
Total 180 120109 3290289 449 (100.0%)
Longest dialysis history42 years and 8 months  
(The above data were obtained from the patient survey)

As determined from the facility survey, the number of new patients who were started on dialysis each year continuously decreased from 38 180 in 2008 to 37 566 in 2009 then 37 512 in 2010 (Table 2). The number of new patients each year had increased since the first survey in 1968, but this upward trend appeared to have reversed in recent years, although this cannot be confirmed due to slight differences in questionnaire collection rate across survey years. Nevertheless, recent measures of chronic kidney disease (CKD) promoted by the Japan Association of Chronic Kidney Disease Initiative (J-CKDI) have produced favorable results and a potential explanation for the downward trend in the number of new dialysis patients.

Table 2. Changes in number of dialysis patients (tabulated results of facility survey)
Year1991199219931994199519961997199819992000
Chronic dialysis patients116 303123 926134 298143 709154 413167 192175 988185 322197 213206 134
Number of patients newly introduced to dialysis20 87722 47523 87424 29626 39828 40928 87029 64131 48332 018
Number of deceased patients9 72211 62112 14313 18714 40615 17416 10216 68718 52418 938
Patients per million943.8995.81 076.41 149.41 229.71 328.41 394.91 465.21 556.71 624.1
Response rate of facility survey (%)99.399.499.599.799.899.899.799.799.799.9
Year 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Chronic dialysis patients219 183229 538237 710248 166257 765264 473275 242283 421290 661298 252
Number of patients newly introduced to dialysis33 24333 71033 96635 09436 06336 37336 93438 18037 56637 512
Number of deceased patients19 85020 61421 67222 71523 98324 03425 25327 26627 64628 882
Patients per million1 721.91 801.21 862.71 943.52 017.62 069.92 154.22 219.62 279.52 329.1
Response rate of facility survey (%)99.099.699.198.798.998.498.999.098.598.6

On the other hand, the total number of dialysis patients who died in 2010 was 28 882 (Table 1). Unfortunately, the number of dialysis patients who died each year has continued to increase since the first survey (Table 2).

The total number of dialysis patients in Japan at the end of 2010 was 298 252 (Table 1), an increase of 2.6% from the end of 2009 to the end of 2010 (Table 2). The annual increase in the dialysis patient population in Japan was 4.5% in 2000; the growth rate has clearly slowed down in recent years. If the number of new patients who are started on dialysis continues to decrease while the number of dialysis patients who die continues to increase, the dialysis patient population in Japan is expected to start decreasing in the near future.

Among the 4166 facilities that responded to the questionnaire, the number of bedside consoles was 118 622, an increase of 3643 (3.2%) from the previous year. The total number of patients who received dialysis therapy in all facilities was 116 819 and the maximum dialysis capacity was 395 724 patients in 2010, increases of 2.9% and 3.2% from the previous year, respectively.

The percentage of patients who underwent daytime dialysis increased to 82.5%, an increase of 0.3% from the previous year (82.2%). In contrast, 14.1% of patients underwent nighttime dialysis, a decrease of 0.3% from the previous year (14.4%). The trends toward more daytime dialysis patients and less nighttime dialysis patients were continuously observed over the last 10 years.

The number of patients who underwent home HD was 277, an increase of 41 (17.4%) from the previous year (236 patients). The number of patients who underwent home HD was almost 100 between 1983 and 2005 and has rapidly increased since 2006 although the absolute number of such home HD patients has remained low.

The number of PD + another therapy patients, which started to be investigated in the previous survey, was 1983 at the end of 2010. The number of non-PD + catheter patients was 406. The number of PD dropout patients in 2010 was 137.

According to the patient survey, the longest duration on dialysis was 42 years and 8 months.

The number of dialysis patients per million has increased continuously, reaching 2329.1 at the end of 2010 (Tables 1 and 2). According to a data report from the United States Renal Data System (USRDS) (7), Japan has the second largest dialysis patient population per general population after Taiwan (a comparison based on the data at the end of 2009). Japan also has the second largest number of dialysis patients after the US. Table 3 shows the total number of dialysis patients in each prefecture of Japan determined from the facility survey.

Table 3. Numbers of chronic dialysis patients in prefectures
Names of administrative divisionsDaytimeNighttimeHome hemodialysisPeritoneal dialysisTotal
  1. The number of dialysis patients was calculated based on facility survey data. The total number of chronic dialysis patients is the total of the column for the number of patients in sheet I, and does not necessarily agree with the total number of patients counted according to the method of treatment.

Hokkaido12 6101 341849314 452
Aomori prefecture2 90821801033 229
Iwate prefecture2 43433901302 903
Miyagi prefecture3 8319000634 794
Akita prefecture1 6561450621 863
Yamagata prefecture1 98629021152 393
Fukushima prefecture4 00634901484 503
Ibaraki prefecture6 05584711307 033
Tochigi prefecture4 6397952555 491
Gunma prefecture4 37075401155 239
Saitama prefecture12 6302 1396335915 191
Chiba prefecture10 7681 719127112 759
Tokyo22 6234 93612104828 620
Kanagawa prefecture14 6083 0362059418 258
Niigata prefecture3 6051 03711674 810
Toyama prefecture1 9962601762 333
Ishikawa prefecture2 0313800932 504
Fukui prefecture1 4741770751 726
Yamanashi prefecture1 9252071592 192
Nagano prefecture3 69474511344 574
Gifu prefecture3 64964151454 440
Shizuoka prefecture8 1471 30342649 718
Aichi prefecture12 2963 2383463116 201
Mie prefecture3 32458051174 026
Shiga prefecture2 218442171212 798
Kyoto prefecture4 6071 05722325 898
Osaka prefecture18 0712 8583961321 581
Hyogo prefecture10 4031 7412929612 469
Nara prefecture2 85921851013 184
Wakayama prefecture2 4532671262 747
Tottori prefecture1 1481330951 376
Shimane prefecture1 2261510861 463
Okayama prefecture3 62856812274 424
Hiroshima prefecture6 06457454847 127
Yamaguchi prefecture2 84037201523 364
Tokushima prefecture2 01327401912 478
Kagawa prefecture2 10315052352 493
Ehime prefecture2 98340311563 543
Kochi prefecture1 9502480322 230
Fukuoka prefecture10 5242 327458413 439
Saga prefecture1 7723091222 104
Nagasaki prefecture3 05749231833 735
Kumamoto prefecture4 89696411406 001
Oita prefecture3 27834811383 765
Miyazaki prefecture2 9665930533 612
Kagoshima prefecture4 41755711035 078
Okinawa prefecture3 4056300564 091
Total246 14642 0522779773298 252

Mean age

The dialysis patient population in Japan is getting older yearly. Table 4 shows changes in the mean age of patients obtained from the patient survey. As shown in this table, the mean age of new patients who were started on dialysis in 2010 was 67.8 years (±13.3, ±SD here and hereafter) compared to a mean age of 66.2 years (±12.6) among patients who started dialysis in 2010. The dialysis patient population aged by 6.7 years from the end of 1990 to the end of 2000 and by 5.0 years from the end of 2000 to the end of 2010. Thus, the rate of aging of the dialysis patient population decreased. Similarly, the mean age of incident patients increased by 5.7 years from the end of 1990 to the end of 2000, but by only 4.0 years from the end of 2000 to the end of 2010. These findings show that the rate of aging of new dialysis patients also decreased.

Table 4. Changes in mean age of new patients started on dialysis and of patients at the end of each year
YearMean age of patients newly introduced into dialysis treatment (years old)Mean age of patients at the end of each year (years old)
Mean± SDMean±SD
198351.915.548.313.8
198453.215.349.213.8
198554.415.450.313.7
198655.115.251.113.6
198755.914.952.113.7
198856.914.952.913.6
198957.414.753.813.5
199058.114.654.513.5
199158.114.655.313.5
199259.514.556.013.5
199359.814.456.613.5
199460.414.357.313.5
199561.014.258.013.4
199661.514.258.613.4
199762.214.059.213.4
199862.713.959.913.3
199963.413.960.613.3
200063.813.961.213.2
200164.213.761.613.1
200264.713.662.213.0
200365.413.562.812.9
200465.813.463.312.9
200566.213.463.912.8
200666.413.464.412.8
200766.813.364.912.7
200867.213.365.312.7
200967.313.365.812.6
201067.813.366.212.6

Tables 5 and 6 show the gender and age distributions of patients who started dialysis in 2010 and all dialysis patients in 2010, respectively. Tables 7 and 8 summarize the primary diseases of patients who were started on dialysis in 2010 and all dialysis patients in 2010, respectively. The data in these tables were obtained from the patient survey.

Table 5. Number of new patients started on dialysis in 2010 according to age and sex
Age of the patients when newly introduced into dialysis (years old)Male (%)Female (%)Subtotal (%)No information availableTotal (%)
  • The values in parentheses on the right side of each figure represent the percentage relative to the total in each column.

<58 (0.0)9 (0.1)17 (0.0) 17 (0.0)
5–9 2 (0.0)2 (0.0) 2 (0.0)
10–147 (0.0)2 (0.0)9 (0.0) 9 (0.0)
15–1926 (0.1)15 (0.1)41 (0.1) 41 (0.1)
20–2458 (0.2)30 (0.2)88 (0.2) 88 (0.2)
25–29107 (0.4)52 (0.4)159 (0.4) 159 (0.4)
30–34198 (0.8)109 (0.9)307 (0.8) 307 (0.8)
35–39455 (1.9)215 (1.7)670 (1.8) 670 (1.8)
40–44722 (2.9)271 (2.2)993 (2.7) 993 (2.7)
45–491 024 (4.2)409 (3.3)1 433 (3.9) 1 433 (3.9)
50–541 344 (5.5)563 (4.5)1 907 (5.1) 1 907 (5.1)
55–592 180 (8.9)872 (6.9)3 052 (8.2) 3 052 (8.2)
60–643 389 (13.8)1 407 (11.2)4 796 (12.9) 4 796 (12.9)
65–693 505 (14.3)1 574 (12.5)5 079 (13.7) 5 079 (13.7)
70–743 811 (15.5)1 734 (13.8)5 545 (14.9) 5 545 (14.9)
75–793 781 (15.4)2 059 (16.4)5 840 (15.7) 5 840 (15.7)
80–842 605 (10.6)1 893 (15.1)4 498 (12.1) 4 498 (12.1)
85–891 115 (4.5)1 063 (8.5)2 178 (5.9) 2 178 (5.9)
90–94229 (0.9)242 (1.9)471 (1.3) 471 (1.3)
95≤28 (0.1)27 (0.2)55 (0.1) 55 (0.1)
Total24 592 (100.0)12 548 (100.0)37 140 (100.0) 37 140 (100.0)
No information available683098 98
Total24 66012 57837 238 37 238
Mean66.9169.5267.79 67.79
SD13.0113.6013.27 13.27
Table 6. Number of all dialysis patients in 2010 according to age and sex
Age (years old)Male (%)Female (%)Subtotal (%)No information availableTotal (%)
  • The values in parentheses on the right side of each figure represent the percentage relative to the total in each column.

<517 (0.0)22 (0.0)39 (0.0) 39 (0.0)
5–97 (0.0)12 (0.0)19 (0.0) 19 (0.0)
10–1415 (0.0)8 (0.0)23 (0.0) 23 (0.0)
15–1960 (0.0)38 (0.0)98 (0.0) 98 (0.0)
20–24226 (0.1)115 (0.1)341 (0.1) 341 (0.1)
25–29582 (0.3)337 (0.3)919 (0.3) 919 (0.3)
30–341 453 (0.8)746 (0.7)2 199 (0.8) 2 199 (0.8)
35–393 394 (1.9)1 719 (1.6)5 113 (1.8) 5 113 (1.8)
40–445 688 (3.2)2 689 (2.5)8 377 (2.9) 8 377 (2.9)
45–498 491 (4.7)4 131 (3.8)12 622 (4.4) 12 622 (4.4)
50–5411 574 (6.4)6 151 (5.6)17 725 (6.1) 17 725 (6.1)
55–5919 077 (10.6)10 459 (9.6)29 536 (10.2) 29 536 (10.2)
60–6430 449 (16.9)16 445 (15.0)46 894 (16.2) 46 894 (16.2)
65–6927 343 (15.2)15 817 (14.5)43 160 (14.9) 43 160 (14.9)
70–7426 679 (14.8)15 959 (14.6)42 638 (14.7) 42 638 (14.7)
75–7923 180 (12.9)14 771 (13.5)37 951 (13.1) 37 951 (13.1)
80–8414 445 (8.0)11 442 (10.5)25 887 (8.9) 25 887 (8.9)
85–895 845 (3.2)6 296 (5.8)12 141 (4.2) 12 141 (4.2)
90–941 421 (0.8)1 872 (1.7)3 293 (1.1) 3 293 (1.1)
95≤169 (0.1)300 (0.3)469 (0.2) 469 (0.2)
Total180 115 (100.0)109 329 (100.0)289 444 (100.0) 289 444 (100.0)
No information available5 5 5
Total180 120109 329289 449 289 449
Mean65.4467.4766.21 66.21
SD12.3912.7812.57 12.57
Table 7. Number of new patients started on dialysis in 2010 according to primary disease and their mean age
Primary diseaseNumber of patientsNo information on birth dateTotalMean ageSD
  1. The values in parentheses on the right side of each figure represent the percentage relative to the total in each column. The column “No information on birth date” shows the number of patients who provided no date of birth, such that the calculation of age was impossible.

Chronic glomerulonephritis (%)7 792 (21.0)41 (41.8)7 833 (21.0)67.6014.42
Chronic pyelonephritis (%)301 (0.8) 301 (0.8)66.3815.22
Rapidly progressive glomerulonephritis (%)444 (1.2)2 (2.0)446 (1.2)69.1713.87
Nephropathy of pregnancy/pregnancy toxemia (%)47 (0.1) 47 (0.1)60.8512.54
Other nephritides that cannot be classified (%)147 (0.4)4 (4.1)151 (0.4)62.5818.2
Polycystic kidney (%)894 (2.4)3 (3.1)897 (2.4)61.2613.44
Nephrosclerosis (%)4 345 (11.7)3 (3.1)4 348 (11.7)74.6710.92
Malignant hypertension (%)331 (0.9)1 (1.0)332 (0.9)63.7917.26
Diabetic nephropathy (%)16 225 (43.7)22 (22.4)16 247 (43.6)66.0911.71
SLE nephritis (%)281 (0.8)1 (1.0)282 (0.8)61.4815.46
Amyloidal kidney (%)127 (0.3) 127 (0.3)66.3810.93
Gouty kidney (%)84 (0.2) 84 (0.2)63.2012.44
Renal failure due to congenital abnormality of metabolism (%)30 (0.1) 30 (0.1)47.5024.93
Kidney and urinary tract tuberculosis (%)13 (0.0) 13 (0.0)74.0010.84
Kidney and urinary tract stone (%)67 (0.2) 67 (0.2)69.6311.07
Kidney and urinary tract tumor (%)182 (0.5)2 (2.0)184 (0.5)69.8410.76
Obstructive urinary tract disease (%)86 (0.2) 86 (0.2)69.6415.51
Myeloma (%)138 (0.4) 138 (0.4)69.7710.81
Hypoplastic kidney (%)62 (0.2)1 (1.0)63 (0.2)38.5028.83
Undetermined (%)3 963 (10.7)10 (10.2)3 973 (10.7)71.2113.05
Reintroduction after transplantation (%)227 (0.6)1 (1.0)228 (0.6)55.1915.19
Others (%)1 345 (3.6)7 (7.1)1 352 (3.6)67.9914.45
Total (%)37 131 (100.0)98 (100.0)37 229 (100.0)67.7913.27
No information available9 973.1113.72
Total37 1409837 23867.7913.27
Table 8. Number of all dialysis patients in 2010 according to primary disease and their mean age
Primary diseaseNumber of patientsNo information on birth dateTotalMean ageSD
  1. The values in parentheses on the right side of each figure represent the percentage relative to the total in each column. The column “No information on birth date” shows the number of patients who provided no date of birth, such that the calculation of age was impossible.

Chronic glomerulonephritis (%)104 762 (36.2)1 (20.0)104 763 (36.2)6512.7
Chronic pyelonephritis (%)3 091 (1.1) 3 091 (1.1)63.9514.11
Rapidly progressive glomerulonephritis (%)2 050 (0.7) 2 050 (0.7)66.5513.8
Nephropathy of pregnancy/pregnancy toxemia (%)1 745 (0.6) 1 745 (0.6)61.949.79
Other nephritides that cannot be classified (%)1 324 (0.5) 1 324 (0.5)59.716.51
Polycystic kidney (%)9 765 (3.4) 9 765 (3.4)63.7811.11
Nephrosclerosis (%)21 816 (7.5) 21 816 (7.5)73.5611.82
Malignant hypertension (%)2 329 (0.8) 2 329 (0.8)63.4714.78
Diabetic nephropathy (%)103 820 (35.9)2 (40.0)103 822 (35.9)66.5111.07
SLE nephritis (%)2 403 (0.8) 2 403 (0.8)59.0313.91
Amyloidal kidney (%)494 (0.2) 494 (0.2)65.8311.58
Gouty kidney (%)1 206 (0.4) 1 206 (0.4)66.4811.67
Renal failure due to congenital abnormality of metabolism (%)280 (0.1) 280 (0.1)48.3117.21
Kidney and urinary tract tuberculosis (%)299 (0.1) 299 (0.1)70.479.4
Kidney and urinary tract stone (%)576 (0.2) 576 (0.2)69.7611.25
Kidney and urinary tract tumor (%)762 (0.3) 762 (0.3)70.2311.67
Obstructive urinary tract disease (%)685 (0.2)1 (20.0)686 (0.2)61.4918.07
Myeloma (%)215 (0.1) 215 (0.1)70.2111.17
Hypoplastic kidney (%)582 (0.2) 582 (0.2)41.6219.55
Undetermined (%)23 071 (8.0)1 (20.0)23 072 (8.0)68.6413.24
Reintroduction after transplantation (%)2 119 (0.7) 2 119 (0.7)54.8212.68
Others (%)6 042 (2.1) 6 042 (2.1)64.2915.64
Total (%)289 436 (100.0)5 (100.0)289 441 (100.0)66.2112.57
No information available8 871.513.93
Total289 4445289 44966.2112.57

Primary diseases of dialysis patients

Table 7 shows a summary of the primary diseases of patients who were started on dialysis in 2010. Table 8 shows a summary of the primary diseases of all dialysis patients at the end of 2010.

Table 9 shows changes in the percentage of new patients who were started on dialysis each year with various primary causes of renal failure (primary diseases). The number of new patients with diabetic nephropathy as the primary disease continued to increase until the end of 2009. However, the number of new patients who had diabetic nephropathy as the primary disease and were started on dialysis decreased at the end of 2010; this decrease was observed for the first time in the 20 year history of the survey (16 549 in 2009 and 16 247 in 2010) (5). The percentage of patients with diabetic nephropathy among new patients also decreased to 43.6%, a decrease of 0.9% from 2009 (44.5%). According to the 2007 report of National Health and Nutrition Survey from the Ministry of Health, Labour and Welfare, the number of diabetic patients has continued to increase (8). If the trend of increasing number of diabetic patients among the general population still continues today, the decrease in the number of new patients with diabetic nephropathy who were started on dialysis may indicate that the treatment for diabetic nephropathy has achieved positive results.

Table 9. Changes in percentage of new patients started on dialysis for each year in terms of primary disease
Year19831984198519861987198819891990199119921993199419951996
Diabetic nephropathy15.617.419.621.322.124.326.526.228.128.429.930.731.933.1
Chronic glomerulonephritis60.558.756.054.854.249.947.446.144.242.241.440.539.438.9
Nephrosclerosis3.03.33.53.73.93.94.15.45.55.96.26.16.36.4
Polycystic kidney2.82.83.12.93.23.13.12.93.02.72.62.52.42.5
Rapidly progressive glomerulonephritis0.90.70.91.00.80.90.80.70.60.70.80.80.80.8
SLE nephritis1.11.11.11.20.90.91.01.11.31.31.21.21.11.3
Chronic pyelonephritis2.42.22.12.01.81.81.51.51.71.61.11.41.21.1
Undetermined4.44.04.84.24.13.84.03.33.73.73.33.94.55.0
Year 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Diabetic nephropathy33.935.736.236.638.139.141.041.342.042.943.443.344.543.6
Chronic glomerulonephritis36.635.033.632.532.431.929.128.127.425.623.822.821.921.0
Nephrosclerosis6.86.77.07.67.67.88.58.89.09.410.010.610.711.7
Polycystic kidney2.42.42.22.42.32.42.32.72.32.42.32.52.32.4
Rapidly progressive glomerulonephritis1.10.90.91.01.01.11.21.11.11.21.31.21.21.2
SLE nephritis1.01.11.20.91.00.90.70.80.80.80.80.80.70.8
Chronic pyelonephritis1.21.11.11.01.10.91.00.91.00.80.80.70.70.8
Undetermined5.55.66.17.69.08.48.89.39.59.910.210.610.710.7

The number and percentage of patients with chronic glomerulonephritis, which is currently the second most common primary disease after diabetic nephropathy, have continuously declined in this decade. The percentage of patients with nephrosclerosis as the primary disease was the third highest (11.7%). In relation to the aging of new dialysis patients, the number and percentage of patients with nephrosclerosis continued to increase. The percentage of patients with “unspecified” primary diseases was the fourth highest (10.7%). In addition, polycystic kidney disease, rapidly progressive glomerulonephritis, systemic lupus erythematosus (SLE) nephritis, and chronic pyelonephritis were also observed as primary diseases. However, the percentages of new patients with these primary diseases among all new dialysis patients were 0.8–2.4%, which was much smaller than the percentages of patients with the above top four primary diseases, and showed no marked increase or decrease over 20 years.

Table 10 shows changes in the percentages of all dialysis patients with various primary diseases at the end of each year. Among all dialysis patients, chronic glomerulonephritis was still the most common primary disease. However, the percentage of patients with this primary disease among all dialysis patients continuously decreased. The number of patients with chronic glomerulonephritis at the end of 2010 was 104 763, which also decreased from 2009 (106 002). In contrast, both the number and percentage of patients with diabetic nephropathy continuously increased. The percentage of patients with chronic glomerulonephritis (36.2%) was still slightly higher than that of patients with diabetic nephropathy (35.9%) at the end of 2010. However, diabetic nephropathy will become the most common primary disease among all dialysis patients by the end of 2011 considering the above trends. The primary diseases with the third and fourth highest percentages of patients among all dialysis patients in 2010 were unspecified primary diseases (8.0%) and nephrosclerosis (7.5%), respectively. The percentage of patients with nephrosclerosis among all dialysis patients continuously increased. In addition, polycystic kidney disease, chronic pyelonephritis, SLE nephritis, and rapidly progressive glomerulonephritis were also observed as primary diseases. However, the percentages of patients with these primary diseases were only 0.7–3.4% and showed no marked increase or decrease over the 20-year survey period.

Table 10. Changes in percentage of patients at the end of each year in terms of primary disease
Year19831984198519861987198819891990199119921993199419951996
Chronic glomerulonephritis74.572.172.370.669.467.965.964.161.760.458.857.756.655.4
Diabetic nephropathy7.48.49.410.511.712.814.014.916.417.118.219.220.421.6
Nephrosclerosis1.51.71.92.02.12.12.32.62.93.13.43.63.84.0
Polycystic kidney2.72.93.03.13.13.23.23.33.33.33.33.23.23.2
Chronic pyelonephritis3.13.32.62.42.42.32.22.22.12.01.91.81.71.6
SLE nephritis0.80.80.90.90.90.90.91.01.11.11.11.11.11.1
Rapidly progressive glomerulonephritis0.50.40.50.50.50.50.50.50.50.50.50.50.50.5
Undetermined2.22.32.32.52.62.52.62.62.92.92.93.13.23.6
Year 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Chronic glomerulonephritis54.152.551.149.749.648.246.645.143.642.240.439.037.636.2
Diabetic nephropathy22.724.025.126.027.228.129.230.231.432.333.434.235.135.9
Nephrosclerosis4.24.44.54.85.05.15.35.75.96.26.56.87.17.5
Polycystic kidney3.23.23.23.23.33.33.33.43.33.43.43.43.43.4
Chronic pyelonephritis1.61.51.51.41.41.31.31.31.21.21.21.11.11.1
SLE nephritis1.11.11.11.01.01.00.90.90.90.90.90.80.80.8
Rapidly progressive glomerulonephritis0.60.60.60.60.60.60.60.60.60.60.70.70.70.7
Undetermined3.94.24.45.05.65.96.36.46.67.07.47.67.78.0

Causes of death

As described above, the classification codes for the causes of death were changed in the 2010 survey. Table 11 shows the classification codes for the causes of death used in the 2003–2009 surveys. Table 12 shows the new classification codes adopted in the 2010 survey. In the classification with new codes, various causes of death were reclassified into several groups, each of which was given a group name, to facilitate the search for the name of the corresponding cause of death. The terms of the causes of death basically followed the previous terms that had been used until the 2009 survey. Moreover, acute myocardial infarction leading to death within 30 days after onset was separately classified as a cause of death. Some other terms of the causes of death were also revised for better understanding of respondents. Because these changes led to some items becoming inconsistent with the ICD-10 codes, the ICD-10 codes corresponding to such items were removed.

Table 11. Classification of causes of death used from 2003 to 2009 surveyThumbnail image of
Table 12. Classification of causes of death used from 2010 survey
Classification of causes of deathCode
Without clinical definite diagnosisWith clinical definite diagnosis
Heart diseaseCardiac failure110111
Pulmonary edema (overhydration)120121
Acute cardiac infarction (death within 30 days after onset)130131
Ischemic heart disease (other than acute cardiac infarction)140141
Arrhythmia and conduction defect150151
Endocarditis and valvular disease160161
Other cardiac diseases100101
Cerebrovascular diseaseSubarachnoid hemorrhage210211
Intracerebral hemorrhage220221
Cerebral infarction230231
Other cerebrovascular diseases200201
Infectious diseaseSepticemia310311
Central nervous system infection320321
Pneumonia330331
Influenza340341
Urinary tract infection350351
Infection of gastrointestinal and biliary tracts and peritonitis360361
Fulminant (acute) viral hepatitis370371
Tuberculosis380381
Human immunodeficiency virus (HIV) infection390391
Other infectious diseases300301
Malignant tumorMalignant neoplasm of central nervous system410411
Malignant neoplasm of respiratory system420421
Liver cancer430431
Malignant neoplasm of digestive system excluding liver cancer440441
Malignant neoplasm of breast450451
Malignant neoplasm of genitals460461
Malignant neoplasm of kidney470471
Malignant neoplasm of endocrine glands480481
Malignant neoplasm of hematopoietic and lymphatic tissues490491
Other malignant neoplasms400401
Liver cirrhosisViral cirrhosis510511
Nonviral cirrhosis520521
Digestive diseaseIntestinal hematogenous disorder610611
Ileus620621
Gastrointestinal bleeding630631
Encapsulating peritoneal sclerosis640641
Other gastrointestinal diseases600601
Pulmonary infarction and embolismPulmonary infarction and embolism710711
Cachexia/uremiaCachexia810811
Uremia820821
Dementia830831
Other cachexia/uremia800801
Sudden deathHyperkalemia910911
Sudden death of uncertain cause920921
Suicide/refusal/Suicide010 
death due to disaster or accident/Refusal of treatment (refusal of dialysis)020 
others/UnspecifiedDeath due to disaster or accident030031
Others080081
Unspecified090 

In Table 13, the causes of death shown in Table 12 were further classified. Table 13 shows the correspondence between the items used in the following tables and the causes of death in Table 12.

Table 13. Correspondence between classification of causes of death in questionnaire and tabulation
Cause of death in tabulationCause of death in questionnaire
1983–20022003–20092010 or after
1Cardiac failure01Pericarditis24Cor pulmonale11Cardiac failure
  02Pulmonary edema/congestive cardiac failure25Pericarditis12Pulmonary edema (overhydration)
  05Other cardiac failures26Endocarditis and valvular disease15Arrhythmia and conduction defect
    29Conduction defect16Endocarditis and valvular disease
    31Arrhythmia10Other cardiac diseases
    32Cardiac failure  
    39Pulmonary edema  
2Cerebrovascular disorder09Cerebrovascular disorder33Subarachnoid hemorrhage21Subarachnoid hemorrhage
    34Intracerebral hemorrhage22Intracerebral hemorrhage
    35Cerebral infarction23Cerebral infarction
    36Other cerebrovascular diseases20Other cerebrovascular diseases
3Infectious disease14Septicemia/bacteremia01Tuberculosis31Septicemia
  15Pneumonia/lung suppuration02Septicemia32Central nervous system infection
  16Acute pancreatitis03Acute viral hepatitis33Pneumonia
  19Peritonitis04Fulminant viral hepatitis34Influenza
  20Tuberculosis05Human immunodeficiency virus (HIV) infection35Urinary tract infection
  21Fulminant hepatitis06Other infectious diseases36Infection of gastrointestinal and biliary tracts and peritonitis
    37Influenza37Fulminant (acute) viral hepatitis
    38Pneumonia38Tuberculosis
    42Peritonitis39Human immunodeficiency virus (HIV) infection
    45Acute pancreatitis30Other infectious diseases
4Hemorrhage12Gastrointestinal bleeding46Gastrointestinal bleeding and others63Gastrointestinal bleeding
5Malignant tumor25Malignant tumor (digestive organs)07Malignant neoplasm of digestive system41Malignant neoplasm of central nervous system
  26Malignant tumor (renal and urinary organs)08Malignant neoplasm of respiratory system42Malignant neoplasm of respiratory system
  27Malignant tumor (others)09Malignant neoplasm of bone and cartilage43Liver cancer
    10Malignant neoplasm of skin and soft tissue44Malignant neoplasm of digestive system excluding liver cancer
    11Malignant neoplasm of breast45Malignant neoplasm of breast
    12Malignant neoplasm of female genitals46Malignant neoplasm of genitals
    13Malignant neoplasm of kidney47Malignant neoplasm of kidney
    14Malignant neoplasm of urinary tract and male genitals48Malignant neoplasm of endocrine glands
    15Malignant neoplasm of eyes, brain, and central nervous system49Malignant neoplasm of hematopoietic and lymphatic tissues
    16Malignant neoplasm of endocrine glands40Other malignant neoplasms
    17Malignant neoplasm of lymphatic and hematopoietic tissues  
6Cachexia/Uremia28Cachexia18Other neoplasms and cachexia81Cachexia
  29Uremia47Uremia82Uremia
    53Cachexia83Dementia
      80Other cachexia/uremia
7Cardiac infarction03Cardiomyopathy/Cardiac infarction22Ischemic heart disease13Acute cardiac infarction (death within 30 days after onset)
    27Myocarditis14Ischemic heart disease (other than acute cardiac infarction)
    28Cardiomyopathy  
8Potassium poisoning/Sudden death06Hyperkalemia19Hyperkalemia91Hyperkalemia
  07Sudden death30Cardiac arrest (sudden death)92Sudden death of uncertain cause
9Chronic hepatitis/Cirrhosis22Hepatitis43Hepatic fibrosis and cirrhosis51Viral cirrhosis
  23Cirrhosis  52Nonviral cirrhosis
10Encephalopathy11Dialytic encephalopathy21Dialytic encephalopathy  
11Suicide/Refusal of treatment (dialysis)30Suicide48Suicide01Suicide
  31Refusal of dialysis51Refusal of treatment (refusal of dialysis)02Refusal of treatment (refusal of dialysis)
12Intestinal obstruction24Intestinal obstruction/ischemic enteritis40Intestinal hematogenous disorder61Intestinal hematogenous disorder
    41Ileus62Ileus
      64Encapsulating peritoneal sclerosis
13Pulmonary thrombus/Pulmonary embolus08Pulmonary thrombus/pulmonary infarction23Pulmonary embolism71Pulmonary infarction and embolism
14Death due to disaster32Death due to disaster/Death due to accident49Death due to disaster or accident03Death due to disaster or accident
15Other causes34Others20Dementia08Others
    44Gallbladder and biliary tract diseases60Other gastrointestinal diseases
    52Others  
16Unspecified33Unspecified50Unspecified09Unspecified

Table 14 shows the classification of causes of death of patients who were started on dialysis in 2010 and who died by the end of 2010. Similar to the 2009 results, the leading cause of death of patients who were started on dialysis in 2010 was infectious diseases (26.5%). The second, third, fourth, and fifth leading causes were cardiac failure (24.9%), unspecified causes (9.2%), malignant tumors (12.5%), and cerebrovascular disorder (4.8%), respectively.

Table 14. Classification of causes of death of new patients who were started on dialysis and died in 2010
Cause of deathMaleFemaleSubtotalNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each column.

Cardiac failure (%)441 (23.2)280 (28.1)721 (24.9) 721 (24.9)
Cerebrovascular disorder (%)87 (4.6)51 (5.1)138 (4.8) 138 (4.8)
Infectious disease (%)518 (27.3)248 (24.9)766 (26.5) 766 (26.5)
Hemorrhage (%)45 (2.4)17 (1.7)62 (2.1) 62 (2.1)
Malignant tumor (%)254 (13.4)108 (10.8)362 (12.5) 362 (12.5)
Cachexia/Uremia (%)70 (3.7)43 (4.3)113 (3.9) 113 (3.9)
Cardiac infarction (%)58 (3.1)29 (2.9)87 (3.0) 87 (3.0)
Potassium poisoning/Sudden death (%)41 (2.2)24 (2.4)65 (2.2) 65 (2.2)
Chronic hepatitis/Cirrhosis (%)29 (1.5)18 (1.8)47 (1.6) 47 (1.6)
Suicide/Refusal of treatment (dialysis) (%)20 (1.1)10 (1.0)30 (1.0) 30 (1.0)
Intestinal obstruction (%)10 (0.5)10 (1.0)20 (0.7) 20 (0.7)
Pulmonary thrombus/Pulmonary embolus (%)7 (0.4)1 (0.1)8 (0.3) 8 (0.3)
Death due to disaster (%)5 (0.3)3 (0.3)8 (0.3) 8 (0.3)
Other causes (%)140 (7.4)61 (6.1)201 (6.9) 201 (6.9)
Unspecified (%)172 (9.1)93 (9.3)265 (9.2) 265 (9.2)
Subtotal (%)1897 (100.0)996 (100.0)2893 (100.0) 2893 (100.0)
No information available4 4 4
Total19019962897 2897

Table 15 shows the classification of the causes of death of all dialysis patients who died in 2010. Table 16 shows changes in the percentages of the leading causes of death in all dialysis patients. Among all dialysis patients, the leading cause of death was cardiac failure; the percentage of patients who died of cardiac failure in 2010 was 27.0%, a marked increase of 3.4 percentage points from 2009 (23.6%). The percentage of patients who died of cardiac failure among all dialysis patients markedly decreased in the 1990s and remained at nearly 23–26% until 2009. Therefore, the above marked increase in the percentage of patients who died of cardiac failure might have been due to the change in the classification of the causes of death in the 2010 survey. The percentage of patients who died of infectious diseases among all dialysis patients was 20.3% in 2010 and tended to gradually increase over the last 20 years. In contrast, the percentage of patients who died of cerebrovascular disorder tended to decrease and reached 8.1% in 2010. The percentage of patients who died of myocardial infarction also tended to decrease from a peak of 8.4% in 1997; however, it was 4.7% in 2010, an increase of 0.7% from 2009 (4.0%). This might also have been due to the change in the classification of the causes of death in this survey. The percentage of patients who died of malignant tumors tended to increase slightly and reached 9.8% in 2010.

Table 15. Classification of causes of death of patients who died in 2010
Cause of deathMaleFemaleSubtotalNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each column.

Cardiac failure (%)4 467 (25.7)2 877 (29.3)7 344 (27.0) 7 344 (27.0)
Cerebrovascular disorder (%)1 377 (7.9)820 (8.4)2 197 (8.1) 2 197 (8.1)
Infectious disease (%)3 586 (20.6)1 941 (19.8)5 527 (20.3) 5 527 (20.3)
Hemorrhage (%)289 (1.7)191 (1.9)480 (1.8) 480 (1.8)
Malignant tumor (%)1 932 (11.1)744 (7.6)2 676 (9.8) 2 676 (9.8)
Cachexia/Uremia (%)608 (3.5)529 (5.4)1 137 (4.2) 1 137 (4.2)
Cardiac infarction (%)881 (5.1)406 (4.1)1 287 (4.7) 1 287 (4.7)
Potassium poisoning/Sudden death (%)546 (3.1)266 (2.7)812 (3.0) 812 (3.0)
Chronic hepatitis/Cirrhosis (%)211 (1.2)94 (1.0)305 (1.1) 305 (1.1)
Suicide/Refusal of treatment (dialysis) (%)178 (1.0)48 (0.5)226 (0.8) 226 (0.8)
Intestinal obstruction (%)149 (0.9)91 (0.9)240 (0.9) 240 (0.9)
Pulmonary thrombus/Pulmonary embolus (%)48 (0.3)34 (0.3)82 (0.3) 82 (0.3)
Death due to disaster (%)100 (0.6)44 (0.4)144 (0.5) 144 (0.5)
Other causes (%)1 046 (6.0)745 (7.6)1 791 (6.6) 1 791 (6.6)
Unspecified (%)1 974 (11.4)986 (10.0)2 960 (10.9) 2 960 (10.9)
Subtotal (%)17 392 (100.0)9 816 (100.0)27 208 (100.0) 27 208 (100.0)
No information available211233 33
Total17 4139 82827 241 27 241
Table 16. Annual changes in major causes of death
Year19831984198519861987198819891990199119921993199419951996
  1. The values in this table are the percentage of each cause of death relative to the total number of deceased patients in each year.

Cardiac failure30.330.531.333.232.736.533.430.430.531.129.928.225.424.1
Infectious disease11.011.511.512.012.012.211.711.612.111.312.212.613.814.6
Malignant tumor7.76.96.46.95.86.97.68.27.67.17.47.37.27.7
Cerebrovascular disease14.215.414.214.014.212.913.213.913.713.613.514.113.512.9
Cardiac infarction5.34.85.36.16.05.45.35.85.85.85.77.17.57.4
Others5.14.95.74.75.24.84.44.64.44.54.14.55.86.3
Unspecified1.92.02.82.22.41.61.92.11.82.52.62.83.22.5
Year 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Cardiac failure23.924.124.323.225.525.125.025.125.824.924.023.723.627.0
Infectious disease14.915.016.316.616.315.918.518.819.219.918.919.920.720.3
Malignant tumor8.17.77.68.38.58.58.59.09.09.29.29.29.49.8
Cerebrovascular disease12.612.111.311.311.611.210.710.69.89.48.98.68.48.1
Cardiac infarction8.47.97.47.07.47.46.25.45.14.44.44.14.04.7
Others6.77.07.77.99.19.09.710.39.19.59.79.710.06.6
Unspecified3.53.93.68.15.76.65.66.57.38.310.310.910.610.9

Annual crude death rate

The annual crude death rate was calculated from the facility survey data. It shows the percentage of patients who died in a given year with respect to the mean annual number of dialysis patients. The annual crude death rate in 2010 was 9.8%. Table 17 shows the trend of annual crude death rates since 1983. It is expected that the annual crude death rate will increase because of the increase in the number of patients with a poor prognosis, such as older patients who were started on dialysis and patients with diabetic nephropathy and nephrosclerosis. In fact, the annual crude death rate has gradually increased since 2000.

Table 17. Changes in annual crude death rate
YearCrude death rate (%)YearCrude death rate (%)
19839.019979.4
19848.919989.2
19859.119999.7
19869.020009.2
19878.520019.3
19889.220029.2
19897.920039.3
19909.620049.4
19918.920059.5
19929.720069.2
19939.420079.4
19949.520089.8
19959.720099.6
19969.420109.8

Cumulative survival rate of new patients who were started on dialysis each year

The cumulative survival rates of new patients who were started on dialysis from 1983 are summarized by year of introduction (Table 18). Moreover, the one-, five-, 10-, 15-, 20-, and 25-year survival rates of patients who were started on dialysis were extracted from the table and plotted in Figure 1.

Table 18. Cumulative survival rates of new patients started on dialysis since 1983
Year of introductionNumber of patients1-year survival rate2-year survival rate3-year survival rate4-year survival rate5-year survival rate6-year survival rate7-year survival rate8-year survival rate9-year survival rate10-year survival rate11-year survival rate12-year survival rate13-year survival rate14-year survival rate
19839 8800.8190.7470.6820.6330.5890.5560.5230.4850.4560.4250.3950.3720.3480.329
198410 6990.8170.7350.6710.6200.5760.5380.4970.4640.4340.4060.3770.3520.3280.306
198511 6090.7950.7200.6600.6090.5630.5200.4850.4440.4120.3850.3600.3350.3100.288
198612 6180.7990.7240.6660.6170.5650.5200.4790.4440.4070.3780.3510.3270.3050.283
198713 5460.8150.7380.6700.6070.5560.5060.4620.4250.3930.3640.3380.3130.2930.270
198814 7440.8240.7390.6650.6020.5470.4980.4550.4170.3820.3520.3250.3010.2800.258
198914 5490.8480.7600.6860.6170.5600.5110.4650.4260.3910.3590.3330.3080.2860.265
199016 5190.8390.7490.6740.6100.5550.5010.4590.4190.3840.3530.3250.3000.2780.260
199118 1890.8280.7350.6620.5980.5380.4870.4440.4060.3740.3440.3170.2920.2710.252
199219 8790.8210.7270.6500.5870.5300.4810.4370.3990.3670.3390.3130.2890.2700.248
199320 8710.8320.7420.6660.5970.5410.4900.4450.4070.3740.3440.3170.2930.2690.251
199421 3810.8290.7420.6690.6030.5430.4910.4480.4100.3740.3430.3130.2910.2690.248
199522 8540.8400.7530.6780.6090.5520.5030.4600.4210.3850.3530.3240.2990.2750.252
199624 8740.8320.7500.6740.6110.5560.5080.4580.4200.3840.3510.3220.2950.2700.249
199725 4740.8380.7520.6800.6200.5630.5130.4680.4250.3890.3550.3260.2970.273 
199826 7910.8450.7650.6970.6350.5740.5240.4750.4330.3970.3660.3340.306  
199927 7310.8500.7730.7050.6390.5800.5280.4810.4400.4010.3630.331   
200029 2040.8550.7760.7100.6470.5900.5350.4890.4440.4040.368    
200130 7850.8540.7740.7050.6390.5840.5320.4840.4410.401     
200231 4970.8580.7800.7120.6490.5900.5350.4860.442      
200332 5080.8590.7810.7140.6510.5930.5380.489       
200433 6550.8650.7880.7220.6600.6000.546        
200534 7780.8620.7860.7180.6540.596         
200636 1410.8710.7940.7270.665          
200736 9180.8670.7950.727           
200837 9340.8670.798            
200938 3410.873             
Year of introduction Number of patients 15-year survival rate 16-year survival rate 17-year survival rate 18-year survival rate 19-year survival rate 20-year survival rate 21-year survival rate 22-year survival rate 23-year survival rate 24-year survival rate 25-year survival rate 26-year survival rate 27-year survival rate
19839 8800.3070.2880.2720.2550.2410.2260.2130.1990.1890.1790.1660.1560.144
198410 6990.2860.2690.2520.2370.2250.2100.1960.1860.1780.1660.1560.148 
198511 6090.2690.2520.2340.2200.2070.1910.1780.1660.1540.1460.136  
198612 6180.2670.2500.2330.2200.2080.1950.1820.1720.1610.153   
198713 5460.2520.2370.2190.2020.1890.1790.1690.1580.148    
198814 7440.2400.2240.2090.1950.1840.1720.1600.149     
198914 5490.2470.2310.2150.2010.1910.1770.166      
199016 5190.2430.2270.2110.1950.1820.172       
199118 1890.2350.2190.2040.1910.178        
199219 8790.2300.2140.1990.184         
199320 8710.2340.2170.201          
199421 3810.2280.213           
199522 8540.231            
199624 874             
199725 474             
199826 791             
199927 731             
200029 204             
200130 785             
200231 497             
200332 508             
200433 655             
200534 778             
200636 141             
200736 918             
200837 934             
200938 341             
Figure 1.

Changes in cumulative survival rate of patients started on dialysis for each year.

The one- to 10-year survival rates have been increasing since 1992 for patients who were started on dialysis around 1992 or later. This trend may be due to the improvement of anemia therapy using erythropoietin starting at the initial phase of dialysis because the clinical use of genetically modified erythropoietin started around this time.

Current status of dialysate quality control

Frequency of measurement of endotoxin concentration in dialysate (Table 19)

Table 19. Frequencies of measurement of endotoxin concentration in dialysis fluid in different medical organizations (number of bedside consoles ≥1)
Kind of facilityMeasurement frequency of endotoxin concentrationSubtotalUnspecifiedNo information availableTotal
NoneEvery dayEvery weekEvery 2 weeksEvery monthSeveral times per yearOnce a year
  1. Kouseiren: an association for welfare belonging to agricultural cooperative associations.

National Public university hospital (%)2 (3.8)  2 (3.8)32 (61.5)14 (26.9)2 (3.8)52 (100.0)  52
Private university hospital (%)2 (3.2)1 (1.6)3 (4.8)8 (12.7)37 (58.7)8 (12.7)4 (6.3)63 (100.0) 265
National hospital (%)3 (7.7)  1 (2.6)18 (46.2)12 (30.8)5 (12.8)39 (100.0)1 40
Prefectural Municipal Village hospital (%)19 (4.6)2 (0.5)2 (0.5)9 (2.2)247 (60.4)94 (23.0)36 (8.8)409 (100.0)118428
Social insurance hospital (%)2 (3.4) 1 (1.7)6 (10.2)33 (55.9)12 (20.3)5 (8.5)59 (100.0)1 60
“Kouseiren” hospital (%)5 (4.2) 1 (0.8)6 (5.1)82 (69.5)9 (7.6)15 (12.7)118 (100.0)21121
Other public hospital (%)7 (3.9) 7 (3.9)7 (3.9)121 (67.6)23 (12.8)14 (7.8)179 (100.0)2 181
Private general hospital (%)4 (3.7)1 (0.9)3 (2.8)6 (5.5)68 (62.4)16 (14.7)11 (10.1)109 (100.0)31113
Private hospital (%)54 (4.9)6 (0.5)23 (2.1)57 (5.2)693 (63.1)161 (14.7)104 (9.5)1098 (100.0)30131141
Private clinic (%)92 (5.0)11 (0.6)59 (3.2)101 (5.4)1156 (62.4)242 (13.1)193 (10.4)1854 (100.0)42271923
Total (%)190 (4.8)21 (0.5)99 (2.5)203 (5.1)2487 (62.5)591 (14.8)389 (9.8)3980 (100.0)92524124

Among 4124 facilities that have at least one console, 3980 facilities (96.5%) responded to questions regarding the frequency of measurement of endotoxin concentration in the dialysate. The collection rate for these questions increased by 2.5 percentage points from the previous year (94.0%). The endotoxin concentration in the dialysate was measured at least once a year in 95.2% of the facilities that responded to the questionnaire, an increase of 6.0 percentage points from the previous year (89.2%). The number of facilities that carried out the measurement at least once a month, as recommended by the JSDT dialysate quality control standard (9), was 2810 (70.6% of the 3980 facilities that responded to the questions on this item), about a twofold increase from 2009 (1373 facilities, 36.0%). This may be because additional points can be given to facilities that maintain a certain quality of dialysate upon request from the medical insurance system in Japan starting in 2010.

Endotoxin concentration in dialysate (Table 20)

Table 20. Endotoxin concentration in dialysis fluid (EU/mL) in different medical organizations (number of bedside consoles ≥1)
Kind of facilityEndotoxin concentration (EU/mL) in dialysis fluidSubtotalUnspecifiedNo information availableTotal
<0.001≥0.001 <0.01≥0.01 <0.05≥0.05 <0.1≥0.1 <0.25≥0.25 <0.5≥0.5
  1. Kouseiren, an association for welfare belonging to agricultural cooperative associations.

National Public university hospital (%)29 (58.0)15 (30.0)3 (6.0)1 (2.0)1 (2.0)1 (2.0) 50 (100.0) 252
Private university hospital (%)37 (60.7)14 (23.0)4 (6.6)1 (1.6)2 (3.3)1 (1.6)2 (3.3)61 (100.0) 465
National hospital (%)26 (72.2)5 (13.9)3 (8.3) 2 (5.6)  36 (100.0)1340
Prefectural Municipal Village hospital (%)252 (65.3)66 (17.1)36 (9.3)12 (3.1)13 (3.4)4 (1.0)3 (0.8)386 (100.0)1527428
Social insurance hospital (%)36 (64.3)10 (17.9)3 (5.4)2 (3.6)5 (8.9)  56 (100.0)2260
“Kouseiren” hospital (%)71 (63.4)27 (24.1)9 (8.0)3 (2.7)1 (0.9) 1 (0.9)112 (100.0)36121
Other public hospital (%)125 (73.1)24 (14.0)12 (7.0)3 (1.8)3 (1.8)3 (1.8)1 (0.6)171 (100.0)37181
Private general hospital (%)59 (56.2)23 (21.9)10 (9.5)10 (9.5)1 (1.0)1 (1.0)1 (1.0)105 (100.0)35113
Private hospital (%)616 (59.0)244 (23.4)98 (9.4)35 (3.4)27 (2.6)13 (1.2)11 (1.1)1044 (100.0)28691141
Private clinic (%)1092 (62.4)334 (19.1)175 (10.0)67 (3.8)39 (2.2)25 (1.4)19 (1.1)1751 (100.0)501221923
Total (%)2343 (62.1)762 (20.2)353 (9.4)134 (3.6)94 (2.5)48 (1.3)38 (1.0)3772 (100.0)1052474124

There were 3772 facilities that responded to questions regarding the endotoxin concentration in the dialysate (91.5% of the 4124 facilities that have at least one console). The JSDT dialysate quality control standard (9) was less than 0.05 EU/mL, and the number of facilities that satisfied this standard was 3458 (91.7% of the 3772 facilities that responded to the questions on this item). This was a marked increase from 2009 (2798 facilities, 84.2%). The percentage of facilities that reported an endotoxin concentration of 0.5 EU/mL or more decreased to 1.0% from 3.2% in the 2009 survey. It is considered that the change in the unit of endotoxin concentration (from EU/L to EU/mL) in 2008 has become widely known.

Frequency of measurement of bacterial count in dialysate (Table 21)

Table 21. Frequencies of measurement of bacterial count in dialysis fluid in different medical organizations (number of bedside consoles ≥1)
Kind of facilityMeasurement frequency of bacterial count in the dialysis fluidSubtotalUnspecifiedNo information availableTotal
NoneEvery dayEvery weekEvery two weeksEvery monthSeveral times per yearOnce a year
  1. Kouseiren, an association for welfare belonging to agricultural cooperative associations.

National Public university hospital (%)7 (14.0)  1 (2.0)31 (62.0)9 (18.0)2 (4.0)50 (100.0)2 52
Private university hospital (%)6 (9.5)1 (1.6)2 (3.2)6 (9.5)35 (55.6)9 (14.3)4 (6.3)63 (100.0) 265
National hospital (%)9 (23.1)  2 (5.1)15 (38.5)9 (23.1)4 (10.3)39 (100.0)1 40
Prefectural·Municipal·Village hospital (%)66 (16.3)3 (0.7)1 (0.2)8 (2.0)242 (59.6)58 (14.3)28 (6.9)406 (100.0)139428
Social insurance hospital (%)5 (8.8) 1 (1.8)5 (8.8)27 (47.4)13 (22.8)6 (10.5)57 (100.0)3 60
“Kouseiren” hospital (%)7 (5.9)  5 (4.2)82 (68.9)9 (7.6)16 (13.4)119 (100.0)11121
Other public hospital (%)16 (9.1) 4 (2.3)5 (2.9)117 (66.9)18 (10.3)15 (8.6)175 (100.0)51181
Private general hospital (%)7 (6.4) 2 (1.8)7 (6.4)65 (59.6)16 (14.7)12 (11.0)109 (100.0)31113
Private hospital (%)111 (10.3)2 (0.2)23 (2.1)47 (4.4)667 (62.1)131 (12.2)93 (8.7)1074 (100.0)53141141
Private clinic (%)190 (10.5)10 (0.6)44 (2.4)94 (5.2)1095 (60.3)211 (11.6)173 (9.5)1817 (100.0)77291923
Total (%)424 (10.8)16 (0.4)77 (2.0)180 (4.6)2376 (60.8)483 (12.4)353 (9.0)3909 (100.0)158574124

There were 3909 facilities that responded to questions regarding the frequency of measurement of the bacterial count in the dialysate (94.8% of the 4124 facilities that have at least one console). A bacterial test was carried out at 89.2% of the 3909 facilities, a marked increase of 28.5 percentage points from the end of 2009 (60.7%). The percentage of facilities that carried out the test at least once a month, as recommended by the JSDT dialysate quality control standard (9), was 67.8% in 2010, a marked increase from 2009 (25.8%). Similar to the frequency of measurement of endotoxin concentration in the dialysate, this increase is considered to be affected by the change in the medical insurance system in 2010 in which facilities that maintain a certain dialysate quality can request additional points.

Bacterial count in dialysate (Table 22)

Table 22. Number of facilities for different bacterial counts in dialysis fluid (cfu/mL) and cultivation media (number of bedside consoles ≥1)
Media used for bacterial cultivation of dialysis fluidBacterial count in dialysis fluid (cfu/mL)SubtotalUnspecifiedNo information availableTotal
Less than 0.10.1∼1∼10∼100∼
  1. R2A, Reasoner's No. 2 agar, TGEA, tryptone glucose extract agar, §TSA, tryptic soy agar. The values in parentheses under each figure represent the percentage relative to the total in each row.

General agar medium (%)137 (57.6)42 (17.6)32 (13.4)26 (10.9)1 (0.4)238 (100.0)71246
R2A medium (%)1065 (50.7)361 (17.2)401 (19.1)225 (10.7)50 (2.4)2,102 (100.0)2712130
TGEA medium (%)391 (58.7)130 (19.5)108 (16.2)31 (4.7)6 (0.9)666 (100.0)3 669
Blood agar medium (%)12 (57.1)3 (14.3)4 (19.0)2 (9.5) 21 (100.0)2 23
TSA§ medium (%)13 (72.2)2 (11.1)3 (16.7)  18 (100.0)1 19
Other media (%)115 (47.9)48 (20.0)52 (21.7)21 (8.8)4 (1.7)240 (100.0)6 246
Subtotal (%)1733 (52.8)586 (17.8)600 (18.3)305 (9.3)61 (1.9)3285 (100.0)4623333
Unspecified (%)83 (61.9)24 (17.9)17 (12.7)9 (6.7)1 (0.7)134 (100.0)170280584
No information available (%)3 (75.0) 1 (25.0)  4 (100.0) 203207
Total (%)1819 (53.1)610 (17.8)618 (18.1)314 (9.2)62 (1.8)3423 (100.0)2164854124

Bacterial counts in the dialysate were reported by 3423 facilities, 98.2% of which satisfied the JSDT dialysate quality control standard (i.e. less than 100 cfu/mL) (9). The percentage of facilities that satisfied a bacterial count of less than 0.1 cfu/mL in ultrapure dialysate was 53.1%, similar to that at the end of 2009 (54.5%).

Media used for cultivation of bacteria in dialysate (Table 22)

According to the JSDT dialysate quality control standard, oligotrophic media (e.g. Reasoner's no. 2 agar [R2A] and tryptone glucose extract agar [TGEA]) are recommended for the cultivation of bacteria in the dialysate (9). The survey results showed that these media were used by 84.0% of the 3333 facilities that responded to questions regarding the media used for the cultivation of bacteria.

Volume of sample for measurement of bacterial count in dialysate (Table 23)

Table 23. Number of facilities for different bacterial counts in dialysis fluid (cfu/mL) and sampling volumes for measurement of bacterial count (number of bedside consoles ≥1)
Amount of sampleBacterial count in dialysis fluid (cfu/mL)SubtotalUnspecifiedNo information availableTotal
Less than 0.10.1∼1∼10∼100∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

Less than 1 mL (%)176 (66.4)45 (17.0)33 (12.5)11 (4.2) 265 (100.0)13 278
1 mL∼ (%)423 (47.1)155 (17.3)187 (20.8)114 (12.7)19 (2.1)898 (100.0)302930
10 mL∼ (%)517 (50.2)206 (20.0)187 (18.2)100 (9.7)19 (1.8)1029 (100.0)1111041
50 mL∼ (%)493 (56.2)152 (17.3)154 (17.5)63 (7.2)16 (1.8)878 (100.0)6 884
100 mL∼ (%)172 (58.9)45 (15.4)52 (17.8)17 (5.8)6 (2.1)292 (100.0)3 295
500 mL∼ (%)14 (63.6)3 (13.6)2 (9.1)2 (9.1)1 (4.5)22 (100.0)  22
1 L∼ (%)9 (75.0)2 (16.7) 1 (8.3) 12 (100.0)2 14
10 L∼ (%)3 (75.0) 1 (25.0)  4 (100.0)2 6
Subtotal (%)1807 (53.1)608 (17.9)616 (18.1)308 (9.1)61 (1.8)3400 (100.0)6733470
Unspecified (%)12 (52.2)2 (8.7)2 (8.7)6 (26.1)1 (4.3)23 (100.0)149280452
No information available (%)       202202
Total (%)1819 (53.1)610 (17.8)618 (18.1)314 (9.2)62 (1.8)3423 (100.0)2164854124

Generally, the volume of dialysate sampled to measure bacterial count in plate media is less than 1 mL. However, at least 10 mL of a dialysate sample is required to measure a bacterial count lower than 0.1 cfu/mL, which is the count required to maintain an ultrapure dialysate (9). The volume of the sample dialysate used for measurement of bacterial count was 10 mL or higher at 65.2% of the 3470 facilities that responded to questions regarding the volume of the sample.

Installation of ETRFs (Tables 24–27)

Table 24. Percentages of facilities that have bedside consoles with endotoxin retentive filter (ETRF) in different medical organizations (number of bedside consoles ≥1)
Kind of facilityPercentages of facilities that have bedside consoles with ETRF (%)SubtotalNo information availableTotalMeanSD
0% (No ETRF)<10%10∼20∼30∼40∼50∼60∼70∼80∼90∼100% (All consoles equipped with ETRF)
  1. Kouseiren, an association for welfare belonging to agricultural cooperative associations.

National Public university hospital (%)2 (3.8)         5 (9.6)45 (86.5)52 (100.0) 5295.3319.42
Private university hospital (%)1 (1.5) 1 (1.5)1 (1.5) 1 (1.5)1 (1.5)1 (1.5)2 (3.1)1 (1.5)1 (1.5)55 (84.6)65 (100.0) 6592.7720.81
National hospital (%)1 (2.5)     1 (2.5)1 (2.5)1 (2.5)2 (5.0)1 (2.5)33 (82.5)40 (100.0) 4093.6118.52
Prefectural·Municipal·Village hospital (%)19 (4.5)16 (3.8)11 (2.6)5 (1.2)11 (2.6)5 (1.2)7 (1.7)4 (0.9)8 (1.9)14 (3.3)21 (5.0)301 (71.3)422 (100.0)642884.0731.83
Social insurance hospital (%)4 (6.7) 2 (3.3)2 (3.3)3 (5.0) 2 (3.3)1 (1.7)2 (3.3)3 (5.0)7 (11.7)34 (56.7)60 (100.0) 6080.1132.69
“Kouseiren” hospital (%)3 (2.5)4 (3.3)1 (0.8) 7 (5.8)5 (4.2)4 (3.3)4 (3.3)2 (1.7)2 (1.7)8 (6.7)80 (66.7)120 (100.0)112183.6529.37
Other public hospital (%)9 (5.0)3 (1.7)8 (4.4)3 (1.7)4 (2.2) 5 (2.8)5 (2.8)5 (2.8)7 (3.9)6 (3.3)126 (69.6)181 (100.0) 18183.4731.62
Private general hospital (%)8 (7.1)6 (5.3)6 (5.3)4 (3.5) 1 (0.9)2 (1.8)1 (0.9)1 (0.9)3 (2.7)8 (7.1)73 (64.6)113 (100.0) 11378.1537.39
Private hospital (%)91 (8.1)45 (4.0)48 (4.3)31 (2.7)30 (2.7)27 (2.4)23 (2.0)14 (1.2)16 (1.4)32 (2.8)55 (4.9)717 (63.5)1129 (100.0)12114176.9137.01
Private clinic (%)237 (12.5)107 (5.6)93 (4.9)57 (3.0)49 (2.6)26 (1.4)40 (2.1)41 (2.2)41 (2.2)49 (2.6)94 (4.9)1068 (56.2)1902 (100.0)21192370.3740.66
Total (%)375 (9.2)181 (4.4)170 (4.2)103 (2.5)104 (2.5)65 (1.6)85 (2.1)72 (1.8)78 (1.9)113 (2.8)206 (5.0)2532 (62.0)4084 (100.0)40412475.8337.80
Table 25. Numbers of consoles equipped with endotoxin retentive filter (ETRF) and those without ETRF and rate of ETRF installation in different medical organizations (number of bedside consoles ≥ 1)
 Number of consoles with ETRFNumber of consoles without ETRFMean rate of ETRF installationNumber of facilities that responded to questions regarding ETRFsTotal number of consolesNumber of facilities that did not provide the number of consoles with ETRFTotal number of facilities
(Number)(%)(Number)(%)(%)(Number)(%)
  1. Kouseiren, an association for welfare belonging to agricultural cooperative associations.

National Public university hospital4860.56310.1095.33525170.44 52
Private university hospital1 0621.211100.3792.77651 1721.00 65
National hospital3490.40280.0993.61403770.32 40
Prefectural Municipal Village hospital6 6547.601 4314.7584.074228 0856.876428
Social insurance hospital1 1861.362980.9980.11601 4841.26 60
“Kouseiren” hospital2 8083.216172.0583.651203 4252.911121
Other public hospital3 5444.057542.5083.471814 2983.65 181
Private general hospital2 4522.807632.5378.151133 2152.73 113
Private hospital24 88228.448 17127.1276.91112933 05328.10121141
Private clinic44 07950.3717 92759.5070.37190262 00652.71211923
Total87 502100.0030 130100.0075.824084117 632100.00404124
Table 26. Endotoxin concentration in dialysate (EU/mL) in endotoxin retentive filter (ETRF) and non-ETRF facilities (number of bedside consoles ≥1)
ETRFEndotoxin concentration (EU/mL) in dialysis fluidSubtotalUnspecifiedNo information availableTotal
Less than 0.0010.001∼0.01∼0.05∼0.1∼0.25∼0.5∼
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Without ETRF (%)431 (47.2)246 (26.9)126 (13.8)49 (5.4)35 (3.8)16 (1.8)11 (1.2)914 (100.0)301061050
With ETRF (%)1896 (67.3)501 (17.8)222 (7.9)83 (2.9)57 (2.0)31 (1.1)27 (1.0)2817 (100.0)34182869
Subtotal (%)2327 (62.4)747 (20.0)348 (9.3)132 (3.5)92 (2.5)47 (1.3)38 (1.0)3731 (100.0)641243919
Unspecified (%)16 (39.0)15 (36.6)5 (12.2)2 (4.9)2 (4.9)1 (2.4) 41 (100.0)4137119
No information available (%)         8686
Total (%)2343 (62.1)762 (20.2)353 (9.4)134 (3.6)94 (2.5)48 (1.3)38 (1.0)3772 (100.0)1052474124
Table 27. Bacterial counts in dialysis fluid (cfu/mL) in endotoxin retentive filter (ETRF) and non-ETRF facilities (number of bedside consoles ≥1)
ETRFBacterial count in dialysis fluid (cfu/mL)SubtotalUnspecifiedNo information availableTotal
Less than 0.10.1∼1∼10∼100∼
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Without ETRF (%)354 (44.1)158 (19.7)164 (20.4)108 (13.5)18 (2.2)802 (100.0)541941050
With ETRF (%)1456 (56.4)443 (17.2)443 (17.2)197 (7.6)43 (1.7)2582 (100.0)1161712869
Subtotal (%)1810 (53.5)601 (17.8)607 (17.9)305 (9.0)61 (1.8)3384 (100.0)1703653919
Unspecified (%)9 (23.1)9 (23.1)11 (28.2)9 (23.1)1 (2.6)39 (100.0)4634119
No information available (%)       8686
Total (%)1819 (53.1)610 (17.8)618 (18.1)314 (9.2)62 (1.8)3423 (100.0)2164854124

There were 4084 facilities that responded to questions regarding the installation of ETRFs. The percentage of facilities that have at least one bedside console equipped with an ETRF was 90.8% (Table 24), an increase of 3.9 percentage points from 2009 (86.9%). (These data were obtained on the basis of the number of facilities.)

The survey found that 74.4% of bedside consoles were equipped with an ETRF (87 502 of 117 632 bedside consoles) in facilities that responded to the question (Table 25). The percentage of bedside consoles equipped with an ETRF was 68.4% at the end of 2009 and had increased by 6.0 percentage points at the end of 2010.

The facilities that responded to questions regarding endotoxin concentration in the dialysate were divided into two groups: facilities that have at least one bedside console equipped with an ETRF (ETRF facilities) and facilities that have no bedside console equipped with an ETRF (non-ETRF facilities). The endotoxin concentration in the dialysate was compared between the two groups. The percentages of facilities that satisfied an endotoxin concentration below 0.05 EU/mL, which is recommended by the JSDT dialysate quality control standard (9), were 93.0% for ETRF facilities and 87.9% for non-ETRF facilities (Table 26). The percentages of facilities that satisfied a bacterial count below 100 cfu/mL, which is also recommended by the JSDT dialysate quality control standard (9), were 98.3% for ETRF facilities and 97.8% for non-ETRF facilities (Table 27).

Endotoxin concentration and bacterial count in dialysate (Table 28)

Table 28. Endotoxin concentration in dialysate (EU/mL) in different bacterial counts in dialysis fluid (cfu/mL) (number of bedside consoles ≥1)
Bacterial counts in dialysis fluid (cfu/mL)Endotoxin concentration (EU/mL) in dialysis fluidSubtotalUnspecifiedNo information availableTotal
Less than 0.0010.001∼0.01∼0.05∼0.1∼0.25∼0.5∼
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Less than 0.1 (%)1512 (83.5)189 (10.4)64 (3.5)19 (1.0)17 (0.9)5 (0.3)5 (0.3)1811 (100.0)531819
0.1∼ (%)341 (56.2)183 (30.1)43 (7.1)19 (3.1)10 (1.6)9 (1.5)2 (0.3)607 (100.0)12610
1∼ (%)220 (35.8)216 (35.2)122 (19.9)30 (4.9)14 (2.3)6 (1.0)6 (1.0)614 (100.0)22618
10∼ (%)76 (24.4)79 (25.4)79 (25.4)32 (10.3)24 (7.7)14 (4.5)7 (2.3)311 (100.0)12314
100∼ (%)15 (24.6)9 (14.8)8 (13.1)7 (11.5)9 (14.8)4 (6.6)9 (14.8)61 (100.0)1 62
Subtotal (%)2164 (63.6)676 (19.9)316 (9.3)107 (3.1)74 (2.2)38 (1.1)29 (0.9)3404 (100.0)1093423
Unspecified (%)52 (45.6)30 (26.3)9 (7.9)8 (7.0)8 (7.0)3 (2.6)4 (3.5)114 (100.0)8121216
No information available (%)127 (50.0)56 (22.0)28 (11.0)19 (7.5)12 (4.7)7 (2.8)5 (2.0)254 (100.0)14217485
Total (%)2343 (62.1)762 (20.2)353 (9.4)134 (3.6)94 (2.5)48 (1.3)38 (1.0)3772 (100.0)1052474124

Table 28 shows the endotoxin concentrations and bacterial counts in the dialysate in the facilities. Among the 4124 facilities, 1512 (36.7%) satisfied both an endotoxin concentration below 0.001 EU/mL (lower than the detection limit) and a bacterial count below 0.1 cfu/mL, which define an ultrapure dialysate. There were facilities that reported an endotoxin concentration higher than the standards and a bacterial count lower than the standards, and vice versa. These facilities are required to optimize the method of sampling dialysate for measurement, the method of managing ETRFs, and cleaning and sterilization of dialysis equipment. According to the JSDT dialysate quality control standard (9), both the endotoxin concentration and bacterial count in the dialysate must be measured

History of undergoing CTx

History of undergoing CTx by different dialysis methods (Table 29)

Table 29. History of undergoing carpal tunnel release surgery (CTx) for different dialysis methods (for all target patients)
Dialysis methodWithout undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row. HD, hemodialysis, HDF, hemodiafiltration, HF, hemofiltration, PD, peritoneral dialysis.

Facility HD (%)204 374 (96.7)6984 (3.3)211 358 (100.0)206849 547262 973
HDF (%)10 893 (88.0)1482 (12.0)12 375 (100.0)57243514 867
HF (%)82 (97.6)2 (2.4)84 (100.0) 68152
Hemoadsorption (%)284 (17.3)1360 (82.7)1 644 (100.0)42351 883
Home HD (%)147 (96.7)5 (3.3)152 (100.0)1123276
PD (%)6 012 (98.8)71 (1.2)6 083 (100.0)12830879 298
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449

The 2010 survey investigated the current status of dialysis amyloidosis for the first time in 11 years by inquiring about the history of patients undergoing CTx, an indicator of this complication. As a result, valid responses were obtained from 231 696 patients (collection rate of 80.0%). The percentage of patients who had undergone CTx was 4.3%, which was smaller than that determined in the 1999 survey (5.5%) (3). The patients who had undergone CTx were treated by HDF or hemoadsorption at high percentages.

History of undergoing CTx for each gender and various age groups (Tables 30 and 31)

Table 30. History of undergoing carpal tunnel release surgery (CTx) for each gender (for all target patients)
GenderWithout undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Male (%)139 320 (96.5)4999 (3.5)144 319 (100.0)140034 401180 120
Female (%)82 472 (94.4)4905 (5.6)87 377 (100.0)85821 094109 329
Subtotal (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449
No information available (%)      
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449
Table 31. History of undergoing carpal tunnel release surgery (CTx) for various age groups (for all target patients)
Age (years old)Without undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

<15 (%)55 (100.0) 55 (100.0) 2681
15∼ (%)1 069 (99.6)4 (0.4)1 073 (100.0)102751 358
30∼ (%)12 436 (98.9)136 (1.1)12 572 (100.0)1163 00115 689
45∼ (%)45 937 (95.4)2201 (4.6)48 138 (100.0)44711 29859 883
60∼ (%)100 240 (94.3)6086 (5.7)106 326 (100.0)104325 323132 692
75∼ (%)59 115 (97.6)1446 (2.4)60 561 (100.0)61514 80375 979
90∼ (%)2 936 (99.0)31 (1.0)2 967 (100.0)277683 762
Subtotal (%)221 788 (95.7)9904 (4.3)231 692 (100.0)225855 494289 444
No information available (%)4 (100.0) 4 (100.0) 15
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449
Mean66.2165.3566.1766.6366.3666.21
SD12.698.9212.5612.5812.6612.57

The percentage of patients who had undergone CTx was higher among females (5.6%) than males (3.5%) (Table 30). The percentage of patients who had undergone CTx was the highest for patients aged 60–74 years, above and below which the percentages of such patients were low (Table 31). The dialysis duration for the patients aged 60–74 years may be related to the above-mentioned high percentage of such patients because there is a strong association between dialysis duration and the history of undergoing CTx, as described in the following section.

History of undergoing CTx for different dialysis durations (Table 32)

Table 32. History of undergoing carpal tunnel release surgery (CTx) for different dialysis durations (for all target patients)
dialysis duration (year)Without undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

<2 (%)51 721 (99.6)218 (0.4)51 939 (100.0)52312 75965 221
2∼ (%)58 972 (99.4)366 (0.6)59 338 (100.0)57714 23574 150
5∼ (%)58 113 (99.0)564 (1.0)58 677 (100.0)51414 12973 320
10∼ (%)28 307 (97.4)753 (2.6)29 060 (100.0)2926 98636 338
15∼ (%)13 816 (91.2)1334 (8.8)15 150 (100.0)1823 52018 852
20∼ (%)6 391 (76.8)1929 (23.2)8 320 (100.0)891 92610 335
25∼ (%)4 472 (48.5)4740 (51.5)9 212 (100.0)811 94011 233
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449
Mean6.3922.547.087.156.97.05
SD6.329.267.257.237.057.21

Table 32 shows the number of patients who had undergone CTx for different dialysis durations. The percentage of patients who had undergone CTx increased with dialysis duration; the percentages were 23.2% for a dialysis duration of 20–25 years and 51.5% for a dialysis duration of 25 years or longer. In the 1999 survey, the percentages of such patients were 48.0% for a dialysis duration of 20–25 years and 70.8% for a dialysis duration of 25 years or longer (3). Thus, the percentage of patients who had been treated by dialysis for a long period and had undergone CTx greatly decreased over the last 11 years.

History of undergoing CTx for different primary diseases (Table 33)

Table 33. History of undergoing carpal tunnel release surgery (CTx) for different primary diseases (for all target patients)
Primary diseaseWithout undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Chronic glomerulonephritis (%)77 490 (92.0)6758 (8.0)84 248 (100.0)73619 779104 763
Chronic pyelonephritis (%)2 360 (93.2)173 (6.8)2 533 (100.0)195393 091
Rapidly progressive glomerulonephritis (%)1 588 (97.6)39 (2.4)1 627 (100.0)174062 050
Nephropathy of pregnancy/pregnancy toxemia (%)1 160 (81.9)257 (18.1)1 417 (100.0)163121 745
Other nephritides that cannot be classified (%)1 011 (94.5)59 (5.5)1 070 (100.0)172371 324
Polycystic kidney (%)7 621 (95.9)328 (4.1)7 949 (100.0)901 7269 765
Nephrosclerosis (%)17 395 (98.9)194 (1.1)17 589 (100.0)2154 01221 816
Malignant hypertension (%)1 835 (96.2)73 (3.8)1 908 (100.0)84132 329
Diabetic nephropathy (%)82 402 (98.8)1014 (1.2)83 416 (100.0)75019 656103 822
SLE nephritis (%)1 804 (95.3)89 (4.7)1 893 (100.0)164942 403
Amyloidal kidney (%)366 (97.3)10 (2.7)376 (100.0)5113494
Gouty kidney (%)945 (95.2)48 (4.8)993 (100.0)82051 206
Renal failure due to congenital abnormality of metabolism (%)210 (93.3)15 (6.7)225 (100.0)550280
Kidney and urinary tract tuberculosis (%)217 (88.9)27 (11.1)244 (100.0)154299
Kidney and urinary tract stone (%)444 (94.1)28 (5.9)472 (100.0)599576
Kidney and urinary tract tumor (%)601 (98.5)9 (1.5)610 (100.0)5147762
Obstructive urinary tract disease (%)528 (95.7)24 (4.3)552 (100.0)4130686
Myeloma (%)161 (97.6)4 (2.4)165 (100.0)149215
Hypoplastic kidney (%)455 (97.0)14 (3.0)469 (100.0)5108582
Undetermined (%)17 160 (97.2)487 (2.8)17 647 (100.0)2145 21123 072
Reintroduction after transplantation (%)1 518 (92.0)132 (8.0)1 650 (100.0)564132 119
Others (%)4 521 (97.4)122 (2.6)4 643 (100.0)651 3346 042
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 487289 441
No information available (%)    88
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449

Table 33 shows the number of patients who had undergone CTx for different primary diseases. As mentioned above, there is a strong association between the history of undergoing CTx and dialysis duration. Therefore, the association between primary diseases and the history of undergoing CTx shown in the table is considered to be strongly affected by the dialysis duration of individual patients with each primary disease. To evaluate the effect of each primary disease on the history of undergoing CTx, it is necessary to correct for the dialysis duration of individual patients for each primary disease by some means.

History of undergoing CTx for different predialysis β2m levels (Table 34)

Table 34. History of undergoing carpal tunnel release surgery (CTx) for different β2m levels (mg/L) (for all target patients)
History of undergoing CTx<1010∼20∼30∼40∼50∼60∼SubtotalNo information availableTotalMeanSD
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

Without undergoing CTx (%)1814 (98.9)26 422 (94.5)101 710 (95.1)46 454 (96.9)6430 (97.1)797 (97.0)201 (97.1)183 828 (95.6)37 964 (96.4)221 792 (95.7)26.797.28
With undergoing CTx (%)21 (1.1)1 524 (5.5)5 236 (4.9)1 469 (3.1)194 (2.9)25 (3.0)6 (2.9)8 475 (4.4)1 429 (3.6)9 904 (4.3)25.426.45
Subtotal (%)1835 (100.0)27 946 (100.0)106 946 (100.0)47 923 (100.0)6624 (100.0)822 (100.0)207 (100.0)192 303 (100.0)39 393 (100.0)231 696 (100.0)26.737.26
Unspecified915770743678961 4028562 25828.387.72
No information available1012 41910 5704 920629822018 74136 75455 49527.086.96
Total194530 522118 22353 2797331913233212 44677 003289 44926.777.24

The predialysis β2m level in patients who had undergone CTx (25.4 mg/L) was lower than that for patients who had not (26.8 mg/L). As a reason for this, differences in dialysis duration, residual renal function, and dialysis conditions between the two patient groups are considered. It is necessary to correct for the effects attributable to these factors by some means for accurate comparison of predialysis β2m level between patients who had and had not undergone CTx. The percentages of patients who showed a predialysis β2m level below 30 mg/L were 70.7% and 80.0% of the patients who had not and had undergone CTx, respectively.

History of undergoing CTx for different β2m removal rates (Table 35)

Table 35. History of undergoing carpal tunnel release surgery (CTx) for different β2m removal rates (%) (for patients treated by blood purification therapies using extracorporeal circulation)
β2m removal rates (%)Without undergoing CTxWith undergoing CTxSubtotalUnspecifiedNo information availableTotal
  1. Values in parentheses under each figure represent the percentages relative to the total in each row.

<40 (%)4 510 (97.8)101 (2.2)4 611 (100.0)182294 858
40∼ (%)2 366 (97.9)51 (2.1)2 417 (100.0)141372 568
45∼ (%)3 391 (97.5)86 (2.5)3 477 (100.0)172433 737
50∼ (%)5 163 (97.0)161 (3.0)5 324 (100.0)274365 787
55∼ (%)7 656 (96.8)257 (3.2)7 913 (100.0)337388 684
60∼ (%)9 836 (95.7)440 (4.3)10 276 (100.0)421 11411 432
65∼ (%)10 063 (94.6)574 (5.4)10 637 (100.0)581 14011 835
70∼ (%)6 756 (92.6)542 (7.4)7 298 (100.0)448058 147
75∼ (%)2 858 (90.6)296 (9.4)3 154 (100.0)503173 521
80∼ (%)751 (89.3)90 (10.7)841 (100.0)979929
85∼ (%)124 (90.5)13 (9.5)137 (100.0)28147
90∼ (%)400 (98.0)8 (2.0)408 (100.0) 86494
Sub-toal (%)53 874 (95.4)2619 (4.6)56 493 (100.0)3145 33262 139
No information available (%)167 918 (95.8)7285 (4.2)175 203 (100.0)194450 163227 310
Total (%)221 792 (95.7)9904 (4.3)231 696 (100.0)225855 495289 449
Mean59.6364.9759.8862.9462.6860.13
SD13.8211.5913.7812.7912.0213.65

Table 35 shows the number of patients who had and had not undergone CTx for different β2m removal rates. The β2m removal rate was calculated using the following equation.

image

The mean β2m removal rates were 59.6% and 65.0% for the patients who had not and had undergone CTx, respectively. This indicated that the patients who had undergone CTx were treated by dialysis with a high β2m removal rate.

Items associated with dementia

In the 2010 survey, the onset or non-onset of dementia was investigated as in the 2009 survey (5). The survey items were the same in both years. These items were asked with the following four alternative responses, and the respondents answered accordingly.

A: Without dementia

B: With dementia (requiring no care)

C: With dementia (requiring care)

Z: Unspecified

Dialysis method and dementia (Table 36)

Table 36. Numbers of patients with and without dementia for different dialysis methods (for all dialysis patients)
Dialysis methodDementiaSubtotalUnspecifiedNo information availableTotal
Without dementiaWith dementia (requiring no care)With dementia (requiring care)
  1. The values in parentheses under each figure represent the percentage relative to the total in each row. HD, hemodialysis, HDF, hemodiafiltration, HF, hemofiltration, PD, peritoneal dialysis.

Facility HD (%)193 507 (89.7)9 922 (4.6)12 362 (5.7)215 791 (100.0)258944 593262 973
HDF (%)11 728 (93.4)394 (3.1)440 (3.5)12 562 (100.0)782 22714 867
HF (%)79 (95.2) 4 (4.8)83 (100.0)168152
Hemoadsorption (%)1 568 (97.6)23 (1.4)15 (0.9)1 606 (100.0)82691 883
Home HD (%)186 (99.5) 1 (0.5)187 (100.0) 89276
PD (%)5 790 (94.1)158 (2.6)206 (3.3)6 154 (100.0)1492 9959 298
Total (%)212 858 (90.0)10 497 (4.4)13 028 (5.5)236 383 (100.0)282550 241289 449

Patients determined to have dementia (patients with dementia) accounted for 10.0% of all dialysis patients, almost the same as the percentage in the 2009 survey (9.9%) (5). The percentage of patients with dementia among the patients who underwent HD at facilities was 10.3%, the highest percentage among different dialysis methods. The percentage of patients with dementia among the patients who underwent hemofiltration (HF) was only 4.8% although it was higher in the 2009 survey (20.5%). However, the number of patients who underwent HF and responded to questions regarding dementia was very small; 44 (nine of which were confirmed to have dementia) in the 2009 survey and 83 (four of which were confirmed to have dementia) in the 2010 survey. Therefore, careful consideration is required to determine the significance of the change in percentage.

The percentage of patients with dementia who underwent PD was 5.9%, much lower than for patients who underwent HD at facilities (10.3%). This low percentage may be due to the fact that patients who undergo PD at home are required to have a certain level of cognitive ability. This is similarly considered for the low percentage of patients with dementia who underwent HD at home.

Gender, age, and dementia (Tables 37 and 38)

Table 37. Numbers of male patients with and without dementia and their ages (for patients who underwent HD at facilities three times per week)
Age (years old)DementiaSubtotalUnspecifiedNo information availableTotal
Without dementiaWith dementia (requiring no care)With dementia (requiring care)
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<15 (%)2 (100.0)  2 (100.0)  2
15∼ (%)591 (99.3)3 (0.5)1 (0.2)595 (100.0)561661
30∼ (%)7 376 (99.6)16 (0.2)15 (0.2)7 407 (100.0)457868 238
45∼ (%)27 204 (98.6)206 (0.7)181 (0.7)27 591 (100.0)2183 00030 809
60∼ (%)57 015 (94.0)1848 (3.0)1816 (3.0)60 679 (100.0)6266 74068 045
75∼ (%)25 094 (79.8)2993 (9.5)3340 (10.6)31 427 (100.0)4723 56035 459
90∼ (%)652 (59.7)177 (16.2)264 (24.2)1 093 (100.0)241371 254
Subtotal (%)117 934 (91.6)5243 (4.1)5617 (4.4)128 794 (100.0)139014 284144 468
No information available (%)3 (100.0)  3 (100.0)  3
Total (%)117 937 (91.6)5243 (4.1)5617 (4.4)128 797 (100.0)139014 284144 471
Mean64.5875.6976.7265.5668.8765.8665.62
SD12.128.678.6812.3111.9512.2512.30
Table 38. Numbers of female patients with and without dementia and their ages (for patients who underwent HD at facilities three times per week)
Age (years old)DementiaSubtotalUnspecifiedNo information availableTotal
Without dementiaWith dementia (requiring no care)With dementia (requiring care)
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<15 (%)1 (100.0)  1 (100.0)  1
15∼ (%)292 (99.7) 1 (0.3)293 (100.0)632331
30∼ (%)3 496 (99.3)11 (0.3)12 (0.3)3 519 (100.0)373933 949
45∼ (%)14 060 (98.3)109 (0.8)131 (0.9)14 300 (100.0)125155315 978
60∼ (%)31 467 (92.8)1128 (3.3)1317 (3.9)33 912 (100.0)439392138 272
75∼ (%)16 807 (72.2)2587 (11.1)3900 (16.7)23 294 (100.0)405264326 342
90∼ (%)735 (50.1)215 (14.7)516 (35.2)1 466 (100.0)391861 691
Subtotal (%)66 858 (87.1)4050 (5.3)5877 (7.7)76 785 (100.0)1051872886 564
No information available (%)       
Total (%)66 858 (87.1)4050 (5.3)5877 (7.7)76 785 (100.0)1051872886 564
Mean66.0577.7479.2567.6770.7267.9567.74
SD12.38.518.4912.6112.6112.5812.61

The numbers of patients with and without dementia who underwent HD at facilities were analyzed for both genders and different age groups. Similar to the 2009 survey, the percentage of patients with dementia was high for patients aged 60 years or older (5). Moreover, the percentage of patients with dementia was higher among females than among males for any age group.

Age, ADL, and dementia (Tables 39 and 40)

Table 39. Activities of daily living (ADL) for different patients' age (for patients without dementia who underwent HD at facilities three times per week)
Age (years old)Activities of daily living (ADL)SubtotalUnspecifiedNo information availableTotal
No symptomsModerate symptoms≥50% sitting up≥50% in bedWhole day in bed
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<15 (%)1 (33.3) 1 (33.3) 1 (33.3)3 (100.0)  3
15∼ (%)677 (78.6)150 (17.4)20 (2.3)8 (0.9)6 (0.7)861 (100.0)517883
30∼ (%)7 806 (73.3)2 228 (20.9)380 (3.6)146 (1.4)93 (0.9)10 653 (100.0)4017910 872
45∼ (%)25 896 (64.0)10 798 (26.7)2 223 (5.5)1004 (2.5)514 (1.3)40 435 (100.0)10972041 264
60∼ (%)43 950 (50.7)27 571 (31.8)8 999 (10.4)4017 (4.6)2232 (2.6)86 769 (100.0)248146588 482
75∼ (%)14 025 (34.1)12 998 (31.6)8 415 (20.5)3885 (9.5)1767 (4.3)41 090 (100.0)14067141 901
90∼ (%)265 (19.6)278 (20.5)430 (31.8)267 (19.7)114 (8.4)1 354 (100.0)7261 387
Subtotal (%)92 620 (51.1)54 023 (29.8)20 468 (11.3)9327 (5.1)4727 (2.6)181 165 (100.0)5493078184 792
No information available (%)1 (50.0) 1 (50.0)  2 (100.0) 13
Total (%)92 621 (51.1)54 023 (29.8)20 469 (11.3)9327 (5.1)4727 (2.6)181 167 (100.0)5493079184 795
Mean62.1166.2271.4171.8870.9765.1265.1764.7665.11
SD12.1411.3110.9210.9910.8512.2013.0512.3412.21
Table 40. Activities of daily living (ADL) for different patients' age (for patients with dementia who underwent HD at facilities three times per week)
Age (years old)Activities of daily living (ADL)SubtotalUnspecifiedNo information availableTotal
No symptomsModerate symptoms≥50% sitting up≥50% in bedWhole day in bed
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<15 (%)         
15∼ (%)1 (20.0)1 (20.0)1 (20.0) 2 (40.0)5 (100.0)  5
30∼ (%)13 (24.5)14 (26.4)9 (17.0)10 (18.9)7 (13.2)53 (100.0)1 54
45∼ (%)74 (12.0)104 (16.9)133 (21.6)132 (21.4)174 (28.2)617 (100.0)37627
60∼ (%)424 (7.1)959 (16.0)1512 (25.3)1276 (21.3)1808 (30.2)5 979 (100.0)36946 109
75∼ (%)670 (5.3)1644 (13.1)3452 (27.5)3120 (24.8)3671 (29.2)12 557 (100.0)8417912 820
90∼ (%)47 (4.1)67 (5.8)239 (20.7)358 (31.0)445 (38.5)1156 (100.0)3131 172
Subtotal (%)1229 (6.0)2789 (13.7)5346 (26.2)4896 (24.0)6107 (30.0)20 367 (100.0)12729320 787
No information available (%)         
Total (%)1229 (6.0)2789 (13.7)5346 (26.2)4896 (24.0)6107 (30.0)20 367 (100.0)12729320 787
Mean74.775.6377.6578.3777.6777.3777.3377.2477.37
SD9.808.508.188.638.858.708.808.098.70

In the 2010 survey, ADL of patients was also investigated similarly to the 2009 survey (5). Table 41 shows the alternatives used in the questionnaires and headings in the subsequent tables.

Table 41. Alternatives used in questionnaire on activities of daily living (ADL) and headings in table
 Alternatives used in questionnaire Headings in table
A:The patient can perform social activities without symptoms and behave as he/she was before the onset of dementia without restrictions.No symptoms
B:The patient has moderate symptoms and has trouble with physical work, but can walk and do light and sedentary work, such as light domestic and clerical work.Moderate symptoms
C:The patient can walk and take care of him/herself, but sometimes requires care. The patient can sit up at least half of the day although he/she cannot do light work.≥50% sitting up
D:The patient can take care of him/herself to some extent, but often requires care and is in bed at least half of the day.≥50% in bed
E:The patient cannot take care of him/herself and has to be in bed the whole day, requiring constant care.Whole day in bed
Z:Unspecified or uncategorizedUnspecified

Tables 39 and 40 respectively show the numbers of patients without and with dementia who underwent HD at facilities for different age groups and levels of ADL. Patients with dementia requiring no care and those with dementia requiring care were classified as dementia in these tables. The percentage of patients who showed a low level of ADL tended to increase with age among patients without dementia. In contrast, patients who showed a low level of ADL were observed at a high percentage among patients with dementia for any age group, showing little association between increasing age and decreasing level of ADL.

Age, place of residence, and dementia (Tables 42 and 43)

Table 42. Places of residence for different patients' age (for patients without dementia who underwent HD at facilities three times per week)
Age (years old)Places of residenceSubtotalUnspecifiedNo information availableTotal
HomesCare facilitiesHospitals§
  1. The values in parentheses under each figure represent the percentage relative to the total in each row. Patients' own home (outpatient dialysis, home PD, home HD). Care facilities (e.g. homes with care services, nursing homes such as private-pay nursing homes without national aid and nursing homes for families with financial difficulties, group homes, vocational centers, relief facilities). §Hospitals (e.g. health service facilities for the elderly; beds for general patients, patients of chronic stage, patients requiring rehabilitation, and patients with mental illness and infectious diseases, such as tuberculosis).

<15 (%)2 (66.7) 1 (33.3)3 (100.0)  3
15∼ (%)851 (98.3)4 (0.5)11 (1.3)866 (100.0) 17883
30∼ (%)10 494 (97.7)63 (0.6)185 (1.7)10 742 (100.0)612410 872
45∼ (%)39 305 (96.3)274 (0.7)1215 (3.0)40 794 (100.0)1545541 264
60∼ (%)82 615 (94.4)802 (0.9)4122 (4.7)87 539 (100.0)2192288 482
75∼ (%)36 844 (88.9)965 (2.3)3635 (8.8)41 444 (100.0)1044741 901
90∼ (%)1 072 (78.2)73 (5.3)225 (16.4)1 370 (100.0) 171 387
Subtotal (%)171 183 (93.7)2181 (1.2)9394 (5.1)182 758 (100.0)521982184 792
No information available (%)3 (100.0)  3 (100.0)  3
Total (%)171 186 (93.7)2181 (1.2)9394 (5.1)182 761 (100.0)521982184 795
Mean64.7271.7370.7865.1261.8764.7265.11
SD12.1512.4111.2812.2014.3612.7112.21
Table 43. Places of residence for different patients' age (for patients with dementia who underwent hemodialysis (HD) at facilities three times per week)
Age (years old)Places of residenceSubtotalUnspecifiedNo information availableTotal
HomesCare facilitiesHospitals§
  1. The values in parentheses under each figure represent the percentage relative to the total in each row. Patients' own home (outpatient dialysis, home PD, home HD). Care facilities (e.g. homes with care services, nursing homes such as private-pay nursing homes without national aid and nursing homes for families with financial difficulties, group homes, vocational centers, relief facilities). §Hospitals (e.g. health service facilities for the elderly; beds for general patients, patients of chronic stage, patients requiring rehabilitation, and patients with mental illness and infectious diseases, such as tuberculosis).

<15 (%)       
15∼ (%)4 (80.0) 1 (20.0)5 (100.0)  5
30∼ (%)37 (68.5)8 (14.8)9 (16.7)54 (100.0)  54
45∼ (%)316 (51.0)51 (8.2)253 (40.8)620 (100.0)16627
60∼ (%)3 514 (58.2)474 (7.8)2051 (34.0)6 039 (100.0)2686 109
75∼ (%)7 396 (58.3)1213 (9.6)4071 (32.1)12 680 (100.0)613412 820
90∼ (%)562 (48.3)147 (12.6)455 (39.1)1 164 (100.0) 81 172
Subtotal (%)11 829 (57.5)1893 (9.2)6840 (33.3)20 562 (100.0)921620 787
No information available (%)       
Total (%)11 829 (57.5)1893 (9.2)6840 (33.3)20 562 (100.0)921620 787
Mean77.278.6377.3477.387676.9577.37
SD8.449.009.028.7010.618.368.70

In this survey, the place of residence of individual patients was investigated using the following four alternatives similar to those in the 2009 survey (5).

A: Patients' own home (outpatient dialysis, home PD, home HD);

B: Care facilities (e.g. homes with care services, nursing homes such as private-pay nursing homes without national aids and nursing homes for families with financial difficulties, group homes, vocational centers, relief facilities);

C: Hospitals (e.g. health service facilities for elderly, beds for general patients, patients in chronic stage, patients requiring rehabilitation, and patients with mental illness and infectious diseases such as tuberculosis);

Z: Unspecified or uncategorized.

The numbers of patients without and with dementia who underwent HD at facilities for different age groups and places of residence are shown in Tables 42 and 43, respectively. As with the tables showing the level of ADL, patients with dementia requiring no care and those with dementia requiring care were classified as patients with dementia.

The percentage of patients who stayed at care facilities and hospitals increased with age among patients without dementia. In contrast, the percentage of such patients was high for all age groups among patients with dementia. Moreover, the percentages of such patients were similar among patients aged 45 years or older.

Current status of PD therapy

Among the survey items associated with PD in the patient survey, two items were investigated in all the target facilities: current status of combined use of PD and another therapy and PD duration. The items associated with PD other than the above two items were investigated only in the 3545 facilities that responded to the questionnaires using electronic media.

Current status of combined use of PD and another therapy for different daily amounts of PD solution (Table 44)

Table 44. Current status of combined use of peritoneal dialysis (PD) and another therapy for different daily amounts of PD solution (L/day) (for all PD patients)
Daily amount of PD solutionNon-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<2 (%) 76 (75.2) 17 (16.8)1 (1.0)5 (5.0) 2 (2.0)101 (100.0)  101
2∼ (%) 260 (92.2) 14 (5.0)6 (2.1)1 (0.4) 1 (0.4)282 (100.0)  282
4∼ (%) 737 (91.2) 54 (6.7)15 (1.9)  2 (0.2)808 (100.0)  808
6∼ (%) 1403 (86.7) 175 (10.8)29 (1.8)1 (0.1) 10 (0.6)1618 (100.0)  1618
8∼ (%) 1057 (76.8) 265 (19.3)24 (1.7)2 (0.1) 28 (2.0)1376 (100.0)  1376
10∼ (%) 303 (72.5) 102 (24.4)3 (0.7)2 (0.5) 8 (1.9)418 (100.0)  418
12∼ (%) 143 (67.5) 61 (28.8)4 (1.9)  4 (1.9)212 (100.0)  212
Subtoal (%) 3979 (82.6) 688 (14.3)82 (1.7)11 (0.2) 55 (1.1)4815 (100.0)  4815
No information available (%) 3076 (78.3) 608 (15.5)135 (3.4)39 (1.0)8 (0.2)62 (1.6)3928 (100.0)  3928
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8743
Mean 6.79 8.056.764.75 7.996.98  6.98
SD 2.56 2.772.573.93 2.552.64  2.64

According to the facility survey, the number of PD patients at the end of 2010 was 9773, among which 1983 (20.3%) were PD + another therapy patients. Here, patients who were determined to mainly undergo HD or other therapies more frequently than PD were excluded as PD patients in the table based on the patient survey. Conversely, 8743 patients who responded to questions regarding the current status of the combined use of PD and another therapy with either of the following five answers were classified as patients who underwent mainly PD although they also underwent another therapy, (i.e. PD patients) and were the target group in the tabulation:

  • • PD only;
  • • PD + another therapy once a week;
  • • PD + another therapy twice a week;
  • • PD + another therapy three times a week;
  • • PD + another therapy (other frequencies).

From Table 44, the number of patients who underwent PD and another therapy such as HD was 1688 (19.3% of PD patients).

The daily amount of PD solution was investigated in the facilities that responded to the questionnaires using electronic media and was reported for 4815 patients. Among these patients, the percentage of patients who used 6–8 L of PD solution per day was the highest (33.6%), followed by the patients who used 8–10 L of PD solution per day (28.6%).

However, among 3979 PD-only patients, the percentage of patients who used 6–8 L of PD solution per day was the highest (35.3%). The percentage of PD-only patients who used 10 L of PD solution or higher per day was 11.2%. Among PD + another therapy once a week patients, the percentage of patients who used 8–10 L of PD solution per day was the highest (38.5%) and the percentage of patients who used 10 L of PD solution or higher per day was 23.7%. The daily amount of PD solution tended to be higher among PD + another therapy once a week patients than among PD-only patients.

Combined use of PD and another therapy for various types of PD solution (Table 45)

Table 45. Current status of combined use of peritoneal dialysis (PD) and another therapy for different types of PD solution (for all PD patients)
Type of PD solution usedNon-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

1.5% glucose only (%) 1594 (92.1) 111 (6.4)14 (0.8)4 (0.2) 8 (0.5)1731 (100.0)  1 731
Combined use of 1.5 and 2.5% glucose (%) 637 (74.8) 181 (21.2)24 (2.8)2 (0.2) 8 (0.9)852 (100.0)  852
2.5% glucose only (%) 118 (80.8) 18 (12.3)9 (6.2)  1 (0.7)146 (100.0)  146
1.5% glucose + icodextrin (%) 933 (86.7) 117 (10.9)13 (1.2)1 (0.1) 12 (1.1)1076 (100.0)  1 076
1.5% + 2.5% glucose + icodextrin (%) 460 (71.1) 159 (24.6)11 (1.7)1 (0.2) 16 (2.5)647 (100.0)  647
2.5% glucose + icodextrin (%) 275 (72.6) 81 (21.4)11 (2.9)1 (0.3) 11 (2.9)379 (100.0)  379
Icodextrin only (%) 39 (72.2) 7 (13.0)4 (7.4)4 (7.4)  54 (100.0)  54
4.25% glucose (%) 3 (37.5) 5 (62.5)    8 (100.0)  8
Other solutions (%) 119 (78.3) 25 (16.4)4 (2.6)  4 (2.6)152 (100.0)  152
Subtotal (%) 4178 (82.8) 704 (14.0)90 (1.8)13 (0.3) 60 (1.2)5045 (100.0)  5 045
Unspecified (%) 7 (87.5) 1 (12.5)    8 (100.0)  8
No information available (%) 2870 (77.8) 591 (16.0)127 (3.4)37 (1.0)8 (0.2)57 (1.5)3690 (100.0)  3 690
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8 743

Responses to questions regarding the type of PD solution were obtained from 5045 patients. From Table 45, the percentage of patients who used only 1.5% glucose solution was 34.3% of the 5045 patients. The percentage of patients who used icodextrin in some form was 42.7%. Although most of these patients also used 1.5% or 2.5% glucose solution as well as icodextrin, 54 patients used only icodextrin (1.1%).

The percentages of patients who used only 1.5% glucose solution were 38.2% for the PD-only patients and only 15.8% for the PD + another therapy patients. In contrast, the percentages of patients who used icodextrin were 40.9% for the PD-only patients and 51.8% for the PD + another therapy patients.

Combined use of PD and another therapy for different PET Cr D/P ratios (Table 46)

Table 46. Current status of combined use of peritoneal dialysis (PD) and another therapy for different PET Cr D/P ratios (for all PD patients)
PET CrD/P ratiosNon-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. PET Cr D/P ratio: four-hour creatinine dialysate/plasma ratio in peritoneal equilibrium test.

  2. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.5 (%) 226 (75.3) 56 (18.7)14 (4.7)1 (0.3) 3 (1.0)300 (100.0)  300
0.5∼ (%) 833 (81.0) 164 (15.9)23 (2.2)2 (0.2) 7 (0.7)1029 (100.0)  1029
0.65∼ (%) 902 (83.4) 153 (14.1)15 (1.4)1 (0.1) 11 (1.0)1082 (100.0)  1082
0.81∼ (%) 335 (87.2) 44 (11.5)2 (0.5)1 (0.3) 2 (0.5)384 (100.0)  384
Subtotal (%) 2296 (82.1) 417 (14.9)54 (1.9)5 (0.2) 23 (0.8)2795 (100.0)  2795
No information available (%) 4759 (80.0) 879 (14.8)163 (2.7)45 (0.8)8 (0.1)94 (1.6)5948 (100.0)  5948
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8743
Mean 0.66 0.630.590.55 0.640.65  0.65
SD 0.13 0.140.130.33 0.130.14  0.14

Responses to questions regarding PET Cr D/P ratio were obtained from 2795 patients. Among these patients, the PET Cr D/P ratio was lower than 0.5 (low transporter) in 10.7%, 0.5–0.65 (low-average transporter) in 36.8%, 0.65–0.81 (high-average transporter) in 38.7%, and 0.81–1.0 (high transporter) in 13.7%. The mean PET Cr D/P ratio was 0.65 (±0.14, SD).

The mean PET CR D/P ratio of the PD-only patients was 0.66 (±0.13) whereas that of the PD + another therapy patients tended to be lower as follows: 0.63 (±0.14), 0.59 (±0.13), and 0.55 (±0.33) for the patients who underwent another therapy once, twice, and three times a week, respectively.

Combined use of PD and another therapy for different PD Kt/V-values (Table 47)

Table 47. Current status of combined use of peritoneal dialysis (PD) and another therapy for different PD Kt/V values (for all PD patients)
PD Kt/VNon-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. PD peritoneal dialysis. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.1 (%) 3 (15.8) 14 (73.7) 1 (5.3) 1 (5.3)19 (100.0)  19
0.1∼ (%) 79 (75.2) 21 (20.0)5 (4.8)   105 (100.0)  105
0.4∼ (%) 199 (81.9) 30 (12.3)14 (5.8)   243 (100.0)  243
0.8∼ (%) 446 (87.6) 52 (10.2)7 (1.4)3 (0.6) 1 (0.2)509 (100.0)  509
1.2∼ (%) 712 (83.6) 127 (14.9)7 (0.8)  6 (0.7)852 (100.0)  852
1.7∼ (%) 312 (82.5) 62 (16.4)2 (0.5)  2 (0.5)378 (100.0)  378
2.0∼ (%) 146 (78.9) 34 (18.4)3 (1.6)  2 (1.1)185 (100.0)  185
2.4∼ (%) 99 (86.1) 16 (13.9)    115 (100.0)  115
Subtotal (%) 1996 (83.0) 356 (14.8)38 (1.6)4 (0.2) 12 (0.5)2406 (100.0)  2406
No information avvailable (%) 5059 (79.8) 940 (14.8)179 (2.8)46 (0.7)8 (0.1)105 (1.7)6337 (100.0)  6337
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8743
Mean 1.36 1.340.870.7 1.461.35  1.35
SD 0.63 0.710.570.48 0.550.65  0.65

Responses to questions regarding PD Kt/V were obtained from 2406 patients. The percentages of patients with the following PD Kt/V-values were as follows: lower than 0.8, 15.3%; 0.8–1.2, 21.2%; 1.2–1.7, 35.4%; 1.7–2.0, 15.7%; and 2.0 or higher, 12.5%. The mean PD Kt/V was 1.35 (±0.65). The percentage of the patients with a PD Kt/V of 1.7 or higher, which is recommended in the JSDT guidelines for PD (10), was 28.2%.

Patients who showed PD Kt/V-values of 1.2–1.7 accounted for the highest percentages of the PD-only patients (mean ± SD, 1.36 ± 0.63) and PD + another therapy once a week patients (1.34 ± 0.71). However, the PD Kt/V was low for the PD + another therapy twice a week patients (0.87 ± 0.57) and the PD + another therapy three times a week patients (0.70 ± 0.48). This may be because the patients who underwent another therapy twice or more per week were less frequently treated by PD.

Combined use of PD and another therapy for different daily urine outputs (Table 48)

Table 48. Current status of combined use of PD and another therapy for different daily urine outputs (for all PD patients)
Daily urine outputs (ml/day)Non-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<100 (%) 548 (59.1) 316 (34.1)36 (3.9)6 (0.6) 22 (2.4)928 (100.0)  928
100∼ (%) 454 (75.8) 124 (20.7)13 (2.2)  8 (1.3)599 (100.0)  599
400∼ (%) 729 (91.1) 64 (8.0)3 (0.4)1 (0.1) 3 (0.4)800 (100.0)  800
800∼ (%) 741 (95.6) 29 (3.7)2 (0.3)  3 (0.4)775 (100.0)  775
1200∼ (%) 404 (97.3) 7 (1.7)4 (1.0)   415 (100.0)  415
1600∼ (%) 233 (98.3) 3 (1.3) 1 (0.4)  237 (100.0)  237
Subtotal (%) 3109 (82.8) 543 (14.5)58 (1.5)8 (0.2) 36 (1.0)3754 (100.0)  3754
No information available (%) 3946 (79.1) 753 (15.1)159 (3.2)42 (0.8)8 (0.2)81 (1.6)4989 (100.0)  4989
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8743
Mean 717.56 185.85205.52287.5 158.81626.46  626.46
SD 580.72 312.32381.09635.69 291.39580.66  580.66

Responses to questions regarding daily urine output were obtained from 3754 PD patients. The percentages of patients with the following urine outputs per day were as follows: less than 100 mL, 24.7%; 100–400 mL, 16.0%; 400–800 mL, 21.3%; 800–1200 mL, 20.6%; 1200–1600 mL, 11.1%; and 1600 mL or more, 6.3%. The percentages of patients with a urine output of 400 mL or higher per day, which is an index for patients with effective residual renal function, were 59.3% for the patients who responded to the questions regarding daily urine output, 67.8% for the PD-only patients, and only 19.0% for the PD + another therapy once a week patients.

Combined use of PD and another therapy for different residual-kidney Kt/V-values (Table 49)

Table 49. Current status of combined use of peritoneal dialysis (PD) and another therapy for different residual-kidney Kt/V values (for all PD patients)
Residual-kidney Kt/VNon-PDPD onlyNon-PD + catheterPD + another therapy once a weekPD + another therapy twice a weekPD + another therapy three times a weekPD + another therapy four times a weekPD + another therapy (other frequencies)SubtotalUnspecifiedNo information availableTotal
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.1 (%) 328 (59.4) 197 (35.7)19 (3.4)2 (0.4) 6 (1.1)552 (100.0)  552
0.1∼ (%) 321 (82.7) 64 (16.5)1 (0.3)  2 (0.5)388 (100.0)  388
0.4∼ (%) 494 (95.6) 20 (3.9)3 (0.6)   517 (100.0)  517
0.8∼ (%) 305 (94.1) 16 (4.9)3 (0.9)   324 (100.0)  324
1.2∼ (%) 143 (94.7) 5 (3.3)1 (0.7)2 (1.3)  151 (100.0)  151
1.7∼ (%) 52 (98.1) 1 (1.9)    53 (100.0)  53
2.0∼ (%) 24 (96.0) 1 (4.0)    25 (100.0)  25
2.4∼ (%) 33 (100.0)      33 (100.0)  33
Subtotal (%) 1700 (83.2) 304 (14.9)27 (1.3)4 (0.2) 8 (0.4)2043 (100.0)  2043
No information available (%) 5355 (79.9) 992 (14.8)190 (2.8)46 (0.7)8 (0.1)109 (1.6)6700 (100.0)  6700
Total (%) 7055 (80.7) 1296 (14.8)217 (2.5)50 (0.6)8 (0.1)117 (1.3)8743 (100.0)  8743
Mean 0.63 0.160.230.6 0.030.56  0.56
SD 0.72 0.330.410.69 0.050.70  0.70

Responses to questions regarding residual-kidney Kt/V were obtained from 2043 PD patients. The mean residual-kidney Kt/V was 0.56 (± 0.70) among these patients. It was 0.63 (± 0.72) for the PD-only patients whereas it was 0.16 (± 0.33) for the PD + another therapy once a week patients, which was much lower than that for the PD-only patients.

PD duration for different PET Cr D/P ratios (Table 50)

Table 50. Peritoneal dialysis (PD) duration (year) for different PET Cr D/P ratios (for all PD patients)
PET Cr D/P ratioPD duration (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. PET Cr D/P ratio: four-hour creatinine dialysate/plasma ratio in peritoneal equilibrium test. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.5 (%)56 (21.8)44 (17.1)52 (20.2)65 (25.3)40 (15.6)257 (100.0)433003.673.76
0.5∼ (%)134 (16.4)138 (16.9)247 (30.2)219 (26.8)79 (9.7)817 (100.0)21210293.273.04
0.65∼ (%)134 (15.6)167 (19.5)279 (32.5)213 (24.8)65 (7.6)858 (100.0)22410823.072.98
0.81∼ (%)69 (22.7)73 (24.0)89 (29.3)58 (19.1)15 (4.9)304 (100.0)803842.563.16
Subtotal (%)393 (17.6)422 (18.9)667 (29.8)555 (24.8)199 (8.9)2236 (100.0)55927953.143.14
No information available (%)784 (24.8)523 (16.5)768 (24.3)755 (23.9)334 (10.6)3164 (100.0)278459483.183.56
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39
Mean0.660.670.660.640.610.650.660.65  
SD0.150.140.130.140.140.140.130.14  

There were 2236 patients who responded to both questions regarding PD duration and PET Cr D/P ratio. The percentage of patients who showed a PET Cr D/P ratio of 0.65 or higher (high or high-average transporter) gradually decreased with increasing PD duration as follows: less than 1 year, 51.7%; 1–2 years, 56.9%; 2–4 years, 55.2%; 4–8 years, 48.8%; and 8 years or longer, 40.2%. These values were in disagreement with the previous report that peritoneal permeability increased with PD duration, requiring a detailed examination in the future.

PD duration for different PD Kt/V-values (Table 51)

Table 51. Peritoneal dialysis (PD) duration (year) for different PD Kt/V values (for all PD patients)
PD Kt/VPD duration (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.1 (%)3 (17.6)1 (5.9)3 (17.6)6 (35.3)4 (23.5)17 (100.0)2195.004.64
0.1∼ (%)18 (20.7)8 (9.2)30 (34.5)26 (29.9)5 (5.7)87 (100.0)181053.082.81
0.4∼ (%)71 (31.6)32 (14.2)51 (22.7)48 (21.3)23 (10.2)225 (100.0)182432.883.23
0.8∼ (%)123 (28.8)117 (27.4)116 (27.2)60 (14.1)11 (2.6)427 (100.0)825091.862.11
1.2∼ (%)113 (17.4)120 (18.4)223 (34.3)148 (22.7)47 (7.2)651 (100.0)2018522.942.96
1.7∼ (%)30 (10.5)47 (16.5)84 (29.5)93 (32.6)31 (10.9)285 (100.0)933783.673.05
2.0∼ (%)17 (11.7)23 (15.9)40 (27.6)46 (31.7)19 (13.1)145 (100.0)401853.983.50
2.4∼ (%)16 (17.0)19 (20.2)24 (25.5)25 (26.6)10 (10.6)94 (100.0)211153.313.32
Subtotal (%)391 (20.2)367 (19.0)571 (29.6)452 (23.4)150 (7.8)1931 (100.0)47524062.922.99
No information available (%)786 (22.7)578 (16.7)864 (24.9)858 (24.7)383 (11.0)3469 (100.0)286863373.303.58
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39
Mean1.151.331.341.421.411.321.441.35  
SD0.630.600.650.740.680.670.550.65  

There were 1931 patients who responded to both questions regarding PD duration and PD Kt/V. The percentage of patients who showed a PD Kt/V of 1.7 or higher gradually increased with PD duration: less than 1 year, 16.1%; 1–2 years, 24.3%; 2–4 years, 25.9%; 4–8 years, 36.3%; and 8 years or longer, 40.0%.

PD duration for different daily urine outputs (Table 52)

Table 52. Peritoneal dialysis (PD) duration (year) for different daily urine outputs (mL/day) (for all PD patients)
Daily urine output (ml/day)PD duration (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<100 (%)33 (4.5)32 (4.4)169 (23.1)292 (39.8)207 (28.2)733 (100.0)1959285.914.05
100∼ (%)52 (10.7)101 (20.7)185 (37.9)125 (25.6)25 (5.1)488 (100.0)1115992.902.38
400∼ (%)158 (25.1)142 (22.5)186 (29.5)124 (19.7)20 (3.2)630 (100.0)1708002.252.39
800∼ (%)207 (32.3)145 (22.7)181 (28.3)92 (14.4)15 (2.3)640 (100.0)1357751.872.28
1200∼ (%)120 (37.3)70 (21.7)96 (29.8)33 (10.2)3 (0.9)322 (100.0)934151.531.76
1600∼ (%)73 (37.4)58 (29.7)38 (19.5)23 (11.8)3 (1.5)195 (100.0)422371.562.12
Subtotal (%)643 (21.4)548 (18.2)855 (28.4)689 (22.9)273 (9.1)3008 (100.0)74637543.053.27
No information available (%)534 (22.3)397 (16.6)580 (24.2)621 (26.0)260 (10.9)2392 (100.0)259749893.323.53
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39
Mean947.95820.67612.15392.14156.50630.17611.51626.46  
SD551.67569.87544.15494.48384.71582.35573.93580.66  

There were 3008 patients who responded to both questions regarding PD duration and daily urine output. The percentage of patients with a urine output of 400 mL or higher per day, which is an index for patients with effective residual renal function, decreased with increasing PD duration: less than 1 year, 86.8%; 1–2 years, 75.7%; 2–4 years, 58.6%; 4–8 years, 39.5%; and 8 years or longer, 15.0%.

PD duration for different residual-kidney Kt/V-values (Table 53)

Table 53. Peritoneal dialysis (PD) duration (year) for different residual-kidney Kt/V values (for all PD patients)
Residual-kidney Kt/VPD duration (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.1 (%)16 (3.7)29 (6.7)116 (27.0)181 (42.1)88 (20.5)430 (100.0)1225525.133.58
0.1∼ (%)51 (16.2)63 (20.0)114 (36.2)74 (23.5)13 (4.1)315 (100.0)733882.652.33
0.4∼ (%)107 (25.1)100 (23.5)145 (34.0)66 (15.5)8 (1.9)426 (100.0)915172.032.18
0.8∼ (%)87 (32.5)66 (24.6)72 (26.9)39 (14.6)4 (1.5)268 (100.0)563241.772.03
1.2∼ (%)46 (40.7)29 (25.7)25 (22.1)11 (9.7)2 (1.8)113 (100.0)381511.471.91
1.7∼ (%)18 (46.2)11 (28.2)5 (12.8)5 (12.8) 39 (100.0)14531.151.57
2.0∼ (%)12 (54.5)5 (22.7)1 (4.5)3 (13.6)1 (4.5)22 (100.0)3251.592.87
2.4∼ (%)6 (30.0)3 (15.0)7 (35.0)4 (20.0) 20 (100.0)13332.152.03
Subtotal (%)343 (21.0)306 (18.7)485 (29.7)383 (23.5)116 (7.1)1633 (100.0)41020432.862.96
No information available (%)834 (22.1)639 (17.0)950 (25.2)927 (24.6)417 (11.1)3767 (100.0)293367003.303.55
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39
Mean0.850.680.480.360.140.540.620.56  
SD0.580.550.540.740.340.630.920.70  

There were 1633 patients who responded to both questions regarding PD duration and residual-kidney Kt/V. Similar to the trend of daily urine output, the mean residual-kidney Kt/V decreased with increasing PD duration: less than 1 year, 0.85; 1–2 years, 0.68; 2–4 years, 0.48; 4–8 years, 0.36; and 8 years or longer, 0.14.

PD duration for different total dialysis doses (Table 54)

Table 54. Peritoneal dialysis (PD) duration (year) for different total PD doses (for all PD patients)
Total PD dosePD duraiton (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

<0.1 (%)2 (14.3)1 (7.1)3 (21.4)5 (35.7)3 (21.4)14 (100.0) 144.433.61
0.1∼ (%)  3 (21.4)9 (64.3)2 (14.3)14 (100.0)9235.362.76
0.4∼ (%)7 (24.1)3 (10.3)8 (27.6)8 (27.6)3 (10.3)29 (100.0)1303.283.36
0.8∼ (%)25 (23.6)13 (12.3)28 (26.4)36 (34.0)4 (3.8)106 (100.0)131192.872.53
1.2∼ (%)89 (18.6)93 (19.5)168 (35.1)97 (20.3)31 (6.5)478 (100.0)1125902.762.84
1.7∼ (%)75 (18.4)79 (19.4)132 (32.4)99 (24.3)22 (5.4)407 (100.0)1045112.762.65
2.0∼ (%)80 (24.8)61 (18.9)86 (26.6)68 (21.1)28 (8.7)323 (100.0)723952.853.21
2.4∼ (%)31 (26.3)25 (21.2)29 (24.6)27 (22.9)6 (5.1)118 (100.0)341522.472.58
2.8∼ (%)30 (33.7)22 (24.7)20 (22.5)14 (15.7)3 (3.4)89 (100.0)481371.902.23
Subtotal (%)339 (21.5)297 (18.8)477 (30.2)363 (23.0)102 (6.5)1578 (100.0)39319712.762.84
No information available (%)838 (21.9)648 (17.0)958 (25.1)947 (24.8)431 (11.3)3822 (100.0)295067723.333.58
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39
Mean1.881.881.771.751.701.812.021.85  
SD0.750.620.700.890.610.741.030.81  

The sum of PD Kt/V and residual-kidney Kt/V was defined as the total PD dose and its association with PD duration was examined. Moreover, for PD + another therapy patients, Kt/V attributable to the therapies other than PD was excluded and Kt/V calculated using the above-described equation was used as the total PD dose. There were 1578 patients who responded to all of questions regarding PD duration, PD Kt/V, and residual-kidney Kt/V. The percentages of patients who satisfied a total PD dose of 1.7 or more, which is recommended in the JSDT guidelines for PD (10), decreased with increasing PD duration: less than 1 year, 63.7%; 1–2 years, 63.0%; 2–4 years, 56.0%; 4–8 years, 57.3%; and 8 years or longer, 57.8%. As shown in Table 52, PD Kt/V increased but residual-kidney Kt/V decreased with increasing PD duration. Therefore, the decrease in the total PD dose associated with increasing PD duration is strongly affected by the decrease in residual-kidney Kt/V associated with increasing PD duration.

PET Cr D/P ratio for different methods of exchanging PD solution (Table 55)

Table 55. PET Cr D/P ratio for different methods of exchanging peritoneal dialysis (PD) solution
Dialysis methodDetailed methodPET Cr D/P ratioSubtotalNo information availableTotalMeanSD
<0.50.5∼0.65∼0.81∼
  1. PET Cr D/P ratio: four-hour creatinine dialysate/plasma ratio in peritoneal equilibrium test. Percentage relative to total in row.

PDManual only (%)178 (10.9)598 (36.5)650 (39.7)211 (12.9)1637 (100.0)350351400.650.13
PDAPD only (%)79 (10.2)278 (36.0)280 (36.2)136 (17.6)773 (100.0)153523080.660.15
PDManual + APD (%)41 (10.9)149 (39.7)149 (39.7)36 (9.6)375 (100.0)77011450.640.14
 Total (%)298 (10.7)1025 (36.8)1079 (38.7)383 (13.8)2785 (100.0)58088593

There were 2785 patients who responded to both questions regarding the detailed methods of PD and PET Cr D/P ratio. No significant differences were observed in the trend of PET Cr D/P ratio between the patients who used an automated peritoneal dialysis (APD) machine and those who did not.

PET Cr D/P ratio for different types of PD solution (Table 56)

Table 56. PET Cr D/P ratio for different types of peritoneal dialysis (PD) solution (for all PD patients)
Type of PD solution usedPET Cr D/P ratioSubtotalNo information availableTotalMeanSD
<0.50.5∼0.65∼0.81∼
  1. PET Cr D/P ratio: four-hour creatinine dialysate/plasma ratio in peritoneal equilibrium test. The values in parentheses under each figure represent the percentage relative to the total in each row.

1.5% glucose only (%)124 (13.1)428 (45.1)310 (32.6)88 (9.3)950 (100.0)78117310.620.13
Combined use of 1.5 and 2.5% glucose (%)49 (11.3)177 (40.8)158 (36.4)50 (11.5)434 (100.0)4188520.640.13
2.5% glucose only (%)12 (19.7)19 (31.1)24 (39.3)6 (9.8)61 (100.0)851460.620.15
1.5% glucose + icodextrin (%)49 (7.5)175 (26.6)307 (46.7)126 (19.2)657 (100.0)41910760.690.13
1.5% + 2.5% glucose + icodextrin (%)34 (9.3)127 (34.8)150 (41.1)54 (14.8)365 (100.0)2826470.670.13
2.5% glucose + icodextrin (%)15 (7.6)53 (26.9)90 (45.7)39 (19.8)197 (100.0)1823790.690.14
Icodextrin only (%)2 (7.7)6 (23.1)9 (34.6)9 (34.6)26 (100.0)28540.720.15
4.25% glucose (%)1 (25.0)2 (50.0)1 (25.0) 4 (100.0)480.570.11
Other solutions (%)8 (13.8)24 (41.4)18 (31.0)8 (13.8)58 (100.0)941520.640.14
Subtotal (%)294 (10.7)1011 (36.7)1067 (38.8)380 (13.8)2752 (100.0)229350450.650.14
Unspecified (%)  1 (100.0) 1 (100.0)780.73 
No information available (%)6 (14.3)18 (42.9)14 (33.3)4 (9.5)42 (100.0)364836900.630.16
Total (%)300 (10.7)1029 (36.8)1082 (38.7)384 (13.7)2795 (100.0)594887430.650.14

There were 2752 patients who responded to both questions regarding the type of PD solution and PET Cr D/P ratio. Patients who showed a high PET Cr D/P ratio tended to use icodextrin: 34.0% for low transporters, 35.7% for low-average transporters, 52.1% for high-average transporters, and 60.0% for high transporters.

PD duration and rate of peritonitis per year (Table 57)

Table 57. Peritoneal dialysis (PD) duration for different frequencies of developing peritonitis per year (times/year) (for all PD patients)
Frequencies of developing peritonitis (times/year)PD duration (year)SubtotalNo information availableTotalMeanSD
<11∼2∼4∼8∼
  1. The values in parentheses under each figure represent the percentage relative to the total in each row.

None (%)707 (23.5)531 (17.7)804 (26.7)682 (22.7)282 (9.4)3006 (100.0)84238483.023.33
Once (%)86 (18.4)90 (19.3)136 (29.1)111 (23.8)44 (9.4)467 (100.0)1366033.153.33
Twice (%)16 (15.0)23 (21.5)41 (38.3)20 (18.7)7 (6.5)107 (100.0)271342.812.61
Three times (%)4 (12.1)5 (15.2)10 (30.3)10 (30.3)4 (12.1)33 (100.0)5384.034.05
Four times (%)1 (9.1)2 (18.2)2 (18.2)4 (36.4)2 (18.2)11 (100.0)2134.643.47
Five times or more (%) 2 (20.0)1 (10.0)4 (40.0)3 (30.0)10 (100.0)2126.405.58
Subtotal (%)814 (22.4)653 (18.0)994 (27.4)831 (22.9)342 (9.4)3634 (100.0)101446483.063.33
No information available (%)363 (20.6)292 (16.5)441 (25.0)479 (27.1)191 (10.8)1766 (100.0)232940953.393.49
Total (%)1177 (21.8)945 (17.5)1435 (26.6)1310 (24.3)533 (9.9)5400 (100.0)334387433.173.39

There were 3634 patients who responded to both questions regarding PD duration and the frequencies of developing peritonitis per year. Among these patients, 17.3% developed peritonitis at least once a year. The percentage of patients who developed peritonitis at least once a year was slightly smaller for the patients with a PD duration of less than 1 year than for the patients with a PD duration of 1 year or longer and there was no significant difference in percentage among different PD durations: less than 1 year, 13.1%; 1–2 years, 18.7%; 2–4 years, 19.1%; 4–8 years, 17.9%; and 8 years or longer, 17.3%.

Acknowledgments:

We owe the completion of this survey to the efforts of the members of the subcommittee of local cooperation mentioned in the attached tables and the staff members of dialysis facilities who participated in the survey and responded to the questionnaires. We would like to express our deepest gratitude to all these people.

Attached table:  District Cooperative Committee: Noritomo Itami, Chikara Ooyama, Norio Nakamura, Koji Seino, Kazuyuki Suzuki, Tomoyoshi Kimura, Shigeru Sato, Shigeru Miyagata, Ikuto Masakane, Minoru Ito, Takeshi Watanabe, Kunihiro Yamagata, Eiji Kusano, Shigeaki Muto, Hironobu Kawai, Hiromichi Suzuki, Kaoru Tabei, Noriyoshi Murotani, Takahiro Mochizuki, Makoto Ogura, Masanori Abe, Ryoichi Ando, Akira Ishikawa, Kazuyoshi Okada, Tetsuya Kashiwagi, Satoru Kuriyama, Tsutomu Sanaka, Toshio Shinoda, Eisei Noiri, Matuhiko Hayashi, Sonoo Mizuiri, Koujyu Kamata, Eriko Kinugasa, Takatoshi Kakuta, Fumihiko Koiwa, Toru Hyodo, Junichiro James Kazama, Hiroki Maruyama, Hiroyuki Iida, Yoichi Ishida, Hitoshi Yokoyama, Ryoichi Miyazaki, Haruo Yamashita, Mizuya Fukasawa, Kazuhiko Hora, Yutaka Kannou, Shigeki Sawada, Hiroshi Oda, Akihiko Kato, Noriko Mori, Yuzo Watanabe, Yasuhiko Ito, Shinsuke Nomura, Takashi Udu, Tsuguru Hatta, Noriyuki Iwamoto, Yoshiaki Takemoto, Toshihide Naganuma, Tomoyuki Yamakawa, Takeshi Nakanishi, Sousyu Shin, Katsunori Yoshida, Takashi Shigematsu, Akihisa Nakaoka, Chishio Munemura, Takafumi Ito, Keiko Suzuki, Makoto Hiramatsu, Noriaki Yorioka, Yutaka Nitta, Koichi Uchiyama, Hirofumi Hashimoto, Akira Numata, Atsumi Harada, Masanobu Tanimura, Kenji Yuasa, Hideki Hirakata, Seiya Okuda, Toru Sanai, Takashi Harada, Kenji Arizono, Tadashi Tomo, Syoichi Fujimoto, Toru Ikeda, Tadashi Maeda, Shigeki Toma, Akira Higa, Kunio Yoshihara.

Ancillary