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Keywords:

  • Charlson;
  • comorbidity;
  • selection;
  • index

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References

The study examines selection for kidney transplantation and determines who are referred, how many had contraindications and whether comorbidity indices predict transplant status. Of 113 consecutive adult incident end-stage renal disease (ESRD) patients at this single center 47 (41.6%) were referred. Using published guidelines, 48 (42.5%) had a specific contraindication. However 26 (23%) were neither referred nor had contraindications. An ESRD mortality score, acute renal failure status and albumin were independent predictors of referral but only the mortality score was predictive of contraindication status. The Charlson and ESRD comorbidity indices were less predictive of contraindication or referral status. In a comparison of patients who were Candidates (referred and no contraindication, n = 39) compared to those who were Neither (not referred and no contraindications, n = 26), age was the most discriminating factor (c = 0.99, 95% CI 0.97–1.00). Comorbidity and mortality indices were inferior. Neither patients were older (75 ± 7 years) and had comorbidity scores that were higher than Candidates but similar to those with contraindications (ESRD index; Neither 3.3 ± 2.5, Candidate 1.4 ± 1.8, and contraindication 4.1 ± 3.4). Comorbitity indices do not help explain selection practices whereas age is an important discriminator. How many Neither patients would benefit from transplantation is not known.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References

Kidney transplantation is considered to be the best form of end-stage renal disease (ESRD) therapy. Evidence suggests that kidney transplantation results in superior length and quality of life at less cost (1,2). However, a considerable percentage of patients are never considered for transplantation. Determining who is a candidate for a transplant is one of the most important activities of the nephrologist.

There are national guidelines on the evaluation of patients for transplantation but most do not explicitly state absolute contraindications to transplantation (3–5). The recently published Canadian Transplant Society consensus report looked more closely at eligibility criteria (5). There have been several studies examining selection and center practice (6–9). The study by Holley et al. examined the characteristics of patients accepted or denied access to the wait list (6). However, these patients were referred to a transplant center and were already preselected. A large study of incident hemodialysis patients from several countries reported on demographic and comorbidity with regards to transplant status (7). However patients over the age of 65, patients starting peritoneal dialysis, or preemptive transplanted patients were excluded. Epstein et al. looked at appropriateness of patient selection but did not include patients >54 years of age (8). A European survey of center practice has data relevant to selection practice, however the specifics on numbers declined are not available (9).

There is also recent evidence that comorbidity indices, such as the Charlson index, predict patient survival after a kidney transplant (10,11). There are several studies that show these indices predict patient survival on dialysis (12–14). However, there have been no studies to determine whether these indices predict or assist in patient selection for the transplant wait list.

Our center has a policy that states all patients with ESRD should be considered for transplantation. However, we have never examined compliance to this policy. The overall aim of this study was to examine compliance to the policy. To exclude some of the biases in previous studies we examined all incident adult patients starting ESRD therapy over a 1 year period not simply those age <55 or <65 (7,8).

We set out to answer three specific questions and to test one or more hypotheses for each of these three overriding questions on this cohort of individuals: the first explored referral status. Since the percentage of patients on dialysis that are currently on the list is about 15% in our region, we asked whether a similar percentage of the incident patients would be candidates (15). We also hypothesised that there were a number of demographic, clinical and laboratory variables that would predict referral. Specifically we wanted to test whether comorbidity indices predicted referral status. We also predicted that referral to the transplant coordinator would be late for most patients.

The second separate question asked what percentage of the cohort had a specific medical or surgical contraindication to transplantation at the time of ESRD initiation (contraindication status). We postulated that only a minority of patients would have an absolute contraindication. This was an opportunity to utilize the recently published Canadian consensus guidelines on eligibility (5). We also wanted to test the ability of comorbidity indices to predict contraindication status.

The third inquiry more specifically tested compliance to the policy. After excluding patients with contraindications, we asked whether there would be some remaining individuals, who were neither referred nor had contraindications to transplantation. We also considered that this might be a sizable group, given the older age and comorbidity of incident ESRD patients. We wanted to compare this group to those who were candidates (both referred and no contraindications). Our hypothesis was that comorbidity indices and possibly other variables would predict potential candidacy status.

Materials and Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References

Study population

All consecutive adult (>18 years of age) patients initiating ESRD (preemptive transplantation, peritoneal or hemodialysis) therapy from April 15, 2005, to April 14, 2006, were included. Follow-up study ended on May 1, 2006. Patients with a failed transplant restarting dialysis or receiving a regraft were excluded from this analysis. The center provides dialysis therapy for a population catchment size of about 800 000 citizens in parts of the Provinces of Nova Scotia and Prince Edward Island. Permission for the study was obtained through the center's research ethics board.

Data collection

Patients demographics, height, body weight, comorbidity and laboratory data were obtained from patient records. No new testing was performed. The center's transplant coordinator (JB) provided date of referral and listing on incident patients. Laboratory data (creatinine, urea, albumin and hemoglobin) at ESRD initiation were collected. Glomerular filtration rate (GFR) was calculated by the MDRD formula (16). Data for the Charlson comorbidity and ESRD index were collected at time of dialysis initiation and scored as described by Hemmelgarn et al. (12,14). In short the Charlson index is a collection of 19 comorbid conditions (congestive heart failure, myocardial infarction, liver disease, cancer, dementia, etc.) each given a weight. The sum of these weighted factors is a score that has been found to be a valid and reliable measure of comorbidity for clinical research (17). The ESRD index was derived from the Charlson index but uses only 12 of the 19 conditions with half of them assigned a different weight. The ESRD index, developed and validated in an incident Canadian dialysis population, was slightly better than the Charlson index at predicting patient survival (14). The recent Canadian Wait list consensus paper was used to determine whether a patient was a candidate for listing (5). One of the relative contraindications in this report states that patients not likely to live long enough to survive the wait period should not be considered transplant candidates. We therefore wanted to determine whether Barrett's mortality risk score would predict transplant referral for incident patients (18). This score was also developed and tested in an incident Canadian dialysis population, differs from the others by including age (1–4 points) and includes nine health conditions with varying weights for a score between 1 and 22.

Definitions

To test the specific hypotheses stated in the introduction required patients to be categorized into mutually exclusive groups at each level of analysis or question. The first level of analysis compared those referred (Referred) to the transplantation coordinator versus those not referred (Unreferred). The second level compared those without contraindications versus those with contraindications. Criteria for contraindication was based on the Canadian Transplant Society Consensus Eligibility guidelines (5). The contraindication determination was made by two independent observers (BK and RP). The third level of analysis or question first excluded those with obvious contraindications and then compared potential Candidates (referred and no contraindications) to Neither (not referred and no contraindications).

The study investigators did not interfere with decisions of referral or candidacy. All patients are referred to an ESRD education session. Options including transplantation are presented to the patients at this session. In addition, patients have the option of attending a patient–oriented transplantation session organized by our transplant coordinators that included exposure to transplant recipients. However, referral for transplantation to the coordinator is initiated by the patient's primary nephrologist pre-ESRD. Once on dialysis, any attending nephrologist can refer a patient for transplantation.

Acute kidney disease is defined as a >25 mL/min/1.73 m2 loss of GFR over a 3-month period from a defined disease process (acute tubular necrosis, scleroderma renal crisis, rapidly progressive glomerulonephritis, etc.). Comorbidities were collected from chart review, no independent reevaluation of the primary source documents was undertaken for events occurring >6 months before ESRD initiation. Therefore the diagnosis of congestive heart failure (CHF) and severity were taken from clinic letters or discharge diagnosis. CHF was not used to define a critical contraindication. Patients with malignancy within the recommended wait period were considered a critical contraindication. Peripheral vascular disease (PVD) was defined as prior surgery, amputation, gangrene or symptomatic claudication. A critical contraindication to transplantation was active gangrene or rest pain, recent atheroemboli or uncorrected aortic aneurysm >6 cm. Ischemic heart disease (IHD) was defined as angina with positive stress test, document infarction or invasive therapy for coronary artery disease. A critical contraindication was diagnosed as new onset angina or myocardial infraction within 6 months. A critical contraindication for cerebral vascular disease was defined as completed stroke or treated transient ischemic attack within 6 months. Chronic obstructive lung disease (COLD) was a clinical diagnosis with a critical contraindication being defined as the need for supplemental oxygen. Active infections (sepsis, endocarditis, infected foot ulcers, etc.) were considered critical contraindications. Goodpasture's disease, rapidly progressive glomerulonephritis and other vasculitidies were considered critical contraindications while the patient was on cytotoxic therapy. The Canadian guidelines recommends referral 1 year prior to expected ESRD start (5).

Statistic analysis

This is a descriptive study and data are presented by means ± SD and percentages where appropriate. Differences between groups were by ANOVA or χ2 (Fisher's exact test) where appropriate. Receiver operating characteristic curves were used to determine the ability of comorbidity indices to predict referral, contraindication and candidacy status. Multivariable logistic regression models (backward stepwise) were used to test for predictors for each of the three levels of inquiry (referral status, contraindication status and candidacy status). Variables included into the model were age, sex, laboratory values (albumin, hemoglobin and creatinine) and comorbidity indices. Since age is incorporated in the mortality index, the mortality index was run separately and age was not included as a covariate. Race was not explored, since only 2 of the 113 subjects were nonwhite. Statistical analysis was performed using SSPS (11.1) software.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References

Of the 113 incident patients the etiology of the ESRD was diabetes mellitus 30 (27%), glomerulonephritis 21 (19%), renal vascular disease 19 (17%), adult polycystic kidney disease 17 (15%) and other 26 (23%). ESRD therapy was preemptive transplantation 8 (7%), peritoneal dialysis 13 (12%) and hemodialysis 92 (81%). The demographic and comorbidities for the entire cohort are shown in Table 1. At the end of the study period the center presently has 499 on dialysis and 71 (14%) are on the transplant list. Of these 71, 5 are not yet on dialysis.

Table 1.  Referred versus unreferred
 Referred N = 47Unreferred N = 66Total cohort N = 113Prob
  1. IHD = ischemic heart disease; CHF = congestive heart failure; COLD = chronic obstructive lung disease; GFR = glomerular filtration rate; BMI = body mass index; ESRD = end-stage renal disease.

Age in years (range)51 ± 12 (25–72)69 ± 12 (37–85)62 ± 150.000
Sex (male)34 (68%)45 (72%)79 (70%) 
Acute disease3 (6.4%)23 (35%)26 (23%)0.000
Diabetes mellitus13 (28%)27 (41%)40 (35%) 
Cancer5 (10%)18 (27%)23 (20%)0.031
IHD12 (26%)28 (42%)40 (35%) 
CHF7 (15%)31 (47%)38 (34%)0.001
Stroke5 (11%)11 (17%)16 (14%) 
PVD3 (6.4%)14 (21%)17 (15%)0.034
COLD0 (0%)14 (21%)14 (12%)0.000
Current smoker10 (21%)6 (9.2%)16 (14%) 
GFR (mL/min/1.73 m2)8.1 ± 5.07.8 ± 3.68.0 ± 4.2 
Albumin (g/L)36 ± 530 ± 732 ± 70.000
Hemoglobin (g/L)106 ± 19100 ± 14103 ± 170.000
Weight (kg)86 ± 1878 ± 2182 ± 20 
BMI (kg/m2)30.7 ± 7.829.1 ± 6.329.8 ± 7.0 
Charlson index3.4 ± 1.75.5 ± 2.64.6 ± 2.40.000
ESRD index1.6 ± 2.04.0 ± 3.23.0 ± 3.00.000
Mortality score2.3±1.34.8±1.93.7±2.10.000

Of the 113 patients 47 (42%) were referred to the transplant center for consideration. Most of the patients were referred prior to initiation of ESRD (85%, 40/47) with a median of 296 days prior to ESRD start (1001 pre- to 145 days post-ESRD). However only 21 of the 47 (45%) were referred >365 days prior to dialysis start. Of the 47 referred only 31 have been listed to date with a median of 211 days (17 to 1410 days) from referral to listing. Table 1 also shows the differences between referred and unreferred patients. Referred were in general younger and had less comorbidity (less cancer, CHF, PVD and COLD). Figure 1A shows the ROC curves for the Charlson (c = 0.74, 95% CI 0.65–0.83), ESRD (c = 0.73, 95% CI 0.64–0.82), and Barrett's mortality (c = 0.86, 95% CI 0.79–0.93) indices for predicting referral. Both comorbidity indices were moderately good predictors of referral however there was a significant overlap in scores between groups (Table 1). The correlation between the Charlson and ESRD indices was very high (r= 0.962). The mortality score was significantly better than the comorbidity indices but not better than age alone (c = 0.87, 95% CI 0.81–0.94). The multivariable logistic regression model (Table 2) found that in addition to age, acute status and serum albumin were also independently predictive of referral. Neither comorbidity indices nor individual comorbidities were significant in the model. In a rerunning of the model with the mortality index (without age), serum albumin was also predictive. None of the patients referred have died compared to 12 of the nonreferred.

imageimageimage

Figure 1. (A) ROC for referral Status by comorbidity indices. (B) ROC for contraindication status by comorbidity indices. (C) ROC for candidate versus neither status by comorbidity indices.

Table 2.  Logistic regression models
VariableExp(B)95% CIp ValueModel R2*
  1. *R2= Cox and Snell.

Model 1 (age, sex, acute status, laboratory data, comorbidity indices)
 Referred versus unreferred
 Age (per year)0.8270.766–0.8940.000 
 Acute status0.0750.006–0.8670.038 
 Albumin (g/L)1.231.08–1.390.0010.544
 With contraindication versus without contraindication
 Acute4.741.49–15.10.003 
 ESRD index1.231.07–1.410.0090.210
 Neither versus candidate
 Age (per year)1.791.18–2.700.0060.672
Model 2 (sex, mortality index and laboratory data)
 Referred versus unreferred
 Mortality index0.310.20–0.5040.000 
 Albumin (g/L)1.171.043–1.310.007 
 Acute status0.200.03–1.280.090.500
 With contraindication versus without contraindication
 Mortality index1.6471.271–2.1340.000 
 Acute status3.401.019–11.40.0430.269
 Neither versus candidate
 Mortality index8.332.35–29.50.0000.538

Table 3 shows the characteristics of the 48 (42%) patients who had a contraindication to transplantation at the time of ESRD start. Reasons included malignancy within the recommended wait period (13), recent cardiovascular event (15), active disease (infection (6), scleroderma (1), calciphlaxis (1), rapidly progressive glomerulonephritis (6), PVD (5)) and pregnancy (1). In fact eight of the referred patients had a contraindication to transplantation. Patients with contraindications had more comorbidity (more IHD, COLD and PVD). Despite statistically significant differences by ANOVA, the comorbidity indices (Charlson c = 0.66, 95% CI 0.56–0.76 and ESRD, c = 0.67, 95% CI 0.56–0.76)) were not highly predictive (Figure 1B) of whether a patient had a defined contraindication to transplantation. The mortality index was a better predictor (c = 0.72, 95% CI 0.62–0.81) whereas age was not significant (c = 0.59, 95% CI 0.49–0.70). The logistic regression model (Table 2) found acute kidney disease status and comorbidity index or mortality index were predictive of contraindication status. Only two of the patients without a contraindication have died compared to 10 with a contraindication.

Table 3.  Without versus with contraindication
 Without contraindication N = 65With contraindication N = 48Prob
  1. IHD = ischemic heart disease; CHF = congestive heart failure; COLD = chronic obstructive lung disease; GFR = glomerular filtration rate; BMI = body mass index; ESRD = end-stage renal disease.

Age in years (range)69 ± 16 (25–84)65 ± 11 (37–85)0.045
Sex (male)48 (74%)31 (65%) 
Acute Disease6 (9.2%)20 (42%)0.000
Diabetes mellitus25 (38%)15 (31%) 
Cancer9 (14%)14 (29%) 
IHD16 (25%)24 (50%)0.009
CHF17 (26%)21 (44%) 
Stroke10 (15%)6 (13%) 
PVD5 (7.7%)12 (25%)0.016
COLD4 (6.2%)10 (21%)0.023
Current smoker13 (20%)3 (6.4%)0.053
GFR (mL/min/1.73 m2)8.4 ± 4.67.4 ± 3.5 
Albumin (g/L)34 ± 630 ± 70.001
Hemoglobin (g/L)106 ± 1997 ± 130.008
Charlson index4.0 ± 2.15.5 ± 2.70.002
ESRD index2.2 ± 2.44.1 ± 3.40.001
Mortality score3.1 ± 1.74.7 ± 2.10.000

After excluding patients with a contraindication, Table 4 shows the breakdown into potential candidates (referred and no contraindications) and Neither (not referred and no contraindications). These Neither individuals were older with a mean age of 75 (range 60–84) with a greater level of comorbidity (more DM, CHF, PVD and COLD) and higher mortality risk score. The mortality index had a very high concordance score (c = 0.92, 95% CI 0.86–0.99), however age alone was best (c = 0.99, 95% CI 0.97–1.00). In comparison the other comorbidity indices (Charlson c = 0.76, 95% CI 0.61–0.89) and ESRD (c = 0.75, 95% CI 0.62–0.87) (Figure 1C) were less predictive. In the logistic regression model age was the best discriminator (Table 2).

Table 4.  Candidate (referred and no contraindication) versus neither (not referred and no contraindication)
 Candidate* N = 39Neither N = 26Prob
  1. IHD = ischemic heart disease; CHF = congestive heart failure; COLD = chronic obstructive lung disease; GFR = glomerular filtration rate; BMI = body mass index; ESRD = end-stage renal disease.

Age in years (range)50 ± 12 (25–69)75 ± 7 (60–84)0.000
Sex (male)28 (72%)20 (77%) 
Acute disease2 (5.1%)4 (15%)0.000
Diabetes mellitus12 (31%)13 (50%) 
Cancer3 (7.7%)6 (23%) 
IHD7 (21%)9 (35%) 
CHF6 (12%)11 (42%)0.16
Stroke5 (15%)5 (19%) 
PVD1 (2.9%)4 (13%) 
COLD0 (0%)4 (15%)0.02
Current smoker10 (26%)3 (12%) 
GFR (mL/min/1.73m2)8.4 ± 5.18.2 ± 3.8 
Albumin (g/L)35 ± 532 ± 60.049
Hemoglobin (g/L)108 ± 20105 ± 13 
Charlson index3.3 ± 1.65.1 ± 2.10.000
ESRD index1.4 ± 1.83.3 ± 2.50.001
Mortality score2.1 ± 1.24.6 ± 1.20.000

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References

Despite a center wait list to dialysis ratio of only 14%, a considerably greater proportion (42%) of incident patients have been referred for a transplant. However, slightly less than half had been referred more than a year pre-ESRD start. Almost half (42%) of the cohort had a defined contraindication to transplantation at ESRD start. A significant minority (23%) had no real contraindication to dialysis and were not referred. Not surprisingly this last group has a high degree of comorbidity and were considerably older. Age remains the most important determinant of referral, with almost no referrals over the age of 70 years.

As expected referral status is more likely to occur in the younger patient and less likely to occur in patients with acute disease or low serum albumin. Patients with acute disease or debilitated (low serum albumin) likely will require a period of stability before referral. Although comorbidity scores were significant predictors of referral in a univariate analysis, these indices were not when both age and laboratory variables were included. It is possible that with larger sample sizes or in a different center comorbidity indices would be more predictive of referral status. The concordance statistics (ROC curve analysis) shows that the predictive ability would be modest at best.

The second inquiry concerned contraindication status. Surprisingly age was not a predictor of contraindication status. Acute disease status (i.e. rapidly progressive glomerulonephritis) and high comorbidity index scores were predictive of contraindication status in the multivariate analysis. However, the index scores were only weakly predictive (low concordance (c) statistic of only 0.66) since the timing and severity of the comorbid event play a role in determining whether a patient has a significant contraindication.

In the final inquiry, patients with medical and surgical contraindications were excluded. The remaining without contraindications were divided into those referred (potential Candidates) and those not referred (Neither). Only 23% of patients from the overall cohort fall into this Neither category. Although comorbidity indices were significant predictors by univariate analysis, age was the best overall discriminator. Comorbidity indices are less predictive than age since nearly all age <65 (one exception) without contraindications were referred even with very high comorbidity scores whereas some older patients were not referred despite little or modest comorbidity. Many of these patients were ‘considered’ for transplantation by the attending nephrologists (compliance with the policy). However reason for not referral was age, comorbidity or both. Our program has transplanted patients up to and including age 72, so that there appears to be an age ceiling on acceptance. It is possible that comorbidity scores might be most helpful within an age window between 65 and 75+.

The limitations of our study should be addressed. Our population was somewhat different to the Canadian incident ESRD population of 2002 (15). The etiology of ESRD in the nation (vs. our cohort) was diabetes mellitus 32% (vs. 27%), renal vascular disease/hypertension 18.4% (vs. 17%), adult polycystic kidney disease PCKD 4% (vs. 15%), and glomerulonephritis 12.8% (vs. 19%). The comorbidities were also slightly different in the Canadian incident ESRD population compared to our cohort (CHF 31.4% vs. 34%, PVD 26.6% vs. 15%, cancer 13.3% vs. 20%, and diabetes mellitus 37.6% vs. 35%, respectively). Our crude ratio of patients on the wait list compared to dialysis patients is relatively low at 13.8%, however the national average is similar at 16.6% (2845/17 116) dialysis population (15). Despite these small differences our cohort appears to be a reasonable representation of the Canadian incident ESRD population. We suspect that the discrepancy between the relatively low percentage on the list (14%) and the relatively higher percentage that are candidates (>30%) is that noncandidates accumulate on dialysis and some candidates are transplanted preemptively. A change in acceptance rates is less likely the explanation. Transplant rates have been relatively stable and wait list numbers in our region have not increased (15). Despite the above it is quite possible that other centers in Canada or elsewhere have different practices.

We did not explore other comorbidity indices such as the Davis or Khan indices. These do not appear to have additional predictive value over the Charlson index in the ESRD population (13). We did not perform an analysis of the Index of Coexistent Disease largely because the instrument was time consuming, required trained observers and is not greatly superior to the others tested (19,20). Although, the mortality index reported by Barrett had better discrimination for referral and contraindication status, it does include age (18). Age clearly is the important discriminator in the analysis. Barrett's index was developed to predict mortality in incident dialysis patients with the intention that patients with extremely high mortality rates might not be initiated on treatment (18). Barrett's study also found that the clinician's independent prediction was correlated to the score and marginally better than the predictive model, suggesting that a physician's gestalt for likelihood of survival may be a key factor in selection. Since there is only limited follow-up, the ability of the score to predict mortality, its intended use, was not evaluated in this study. Although, the guidelines expressly state that age is not a reason for nonreferral, it appears to be incorporated into the decision-making process. It is quite possible that some of the elderly patients in the Neither group would benefit from transplantation, but this study was not designed to test this.

The study does also not take into account that some patients within the contraindication group might also become eligible at a later time. It is also possible that some Candidates may develop critical contraindications prior to transplantation or during the evaluation process. At the present time 31 of the 39 Candidates have been listed or transplanted. Of these remaining, four have refused to continue their work-up and deferred transplantation at this time, three remain under evaluation, and one underwent nephrectomy for an incidental renal cell cancer (<6 cm) detected during the transplant evaluation and will be reconsidered. We felt that the analysis could only be done if a consistent easily identifiable time point was used. Time of initiation of ESRD was therefore chosen as the most appropriate time to determine eligibility. It was reassuring to see that most of the individuals were referred prior to the initiation of dialysis. One of the limitations for transplant referral is that some of the patients had an acute disease process or were referred late for their kidney disease to a nephrologist. The seemingly long time from referral to listing can be explained in part because some were referred very early. Actual listing does not occur in our center unless a patient has progressive disease and two consecutive calculated GFRs <15 mL/min.

Low rates of listing the elderly have also been described in the United States. Less than 3% of patients over 70 are listed for transplantation (21). Although, the elderly transplanted do appear to have a survival advantage with transplantation over dialysis, the advantage in absolute years is much less than younger recipients (1,22). Mortality rates even for those elderly listed are extremely high, increase with waiting time and many die on the wait list (22,23). The use of expanded criteria donors to reduce wait times may be of particular benefit to the elderly (24,25). It is not known to what extent age or comorbidity play a role in patient selection in the United States, but there is evidence that it does impact allocation while on the list (26). It is of interest to note that in a survey of deceased organ kidney allocation policy most respondents from the United Kingdom do not feel that age should be used (27). However the subset of elderly (>70 age) in the survey tended to select the younger recipient in preference to the older recipient and only 32.6% felt that age should not be a criteria for allocation. To what extent current selection practices are appropriate remains a challenge to the transplant community at large.

In summary, we found the Canadian guidelines identify a substantial number of incident patients with contraindications at the time of ESRD start. However about 20% have neither contraindication nor are referred. This group is elderly and the majority has comorbidities that impact on life expectancy. Clinicians are probably incorporating these factors into their decision-making process when considering referral. Nonetheless age appears to be the most important factor for determining referral in patients without obvious contraindications to transplantation. The findings do show that referral to the transplant coordinator is late in more than half of potential candidates. Although, the comorbidity indices predict survival in dialysis and transplant recipients, it remains to be determined whether these indices will be of added value in the selection process. It must be stressed that this single center experience cannot be used to infer practice at other centers. We hope our analysis motivates other to examine their selection practice. Selection for the wait list is one of the most important areas of nephrology practice that to date has received limited attention.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. References
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