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Keywords:

  • diabetic foot ulcer;
  • health care disparities;
  • lower extremity amputation;
  • wound healing
  • 糖尿病足溃疡,卫生保健差距,下肢截肢,伤口愈合

Abstract

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

Background

Disparities in diabetic foot ulcer (DFU) treatment outcomes are well described, although few studies identify risk factors contributing to disparate healing and amputation rates. In a unique academic center serving urban public, private, and veteran patients, we investigated amputation and healing rates and specific risk factors for disparate treatment outcomes.

Methods

A retrospective chart review of diabetic patients with a new diagnosis of a foot ulcer at geographically adjacent, but independent public, private, and Veterans Administration (VA) hospitals was conducted. Healing and lower extremity amputation outcomes were assessed.

Results

Across the three hospitals, 234 patients met the inclusion criteria. Patients at the VA hospital were older (mean 72.5 years; P < 0.001) and had gangrenous ulcers (mean 14.1%; P < 0.001) compared with patients in the private and public hospitals. Public hospital patients were mostly Hispanic (mean 54%; P < 0.001) with a shorter duration of diabetes (mean 12.8 years; P = 0.02), but were more poorly controlled than VA and private hospital patients (P ≤ 0.001). Prior amputation (odds ratio [OR] 1.97; P = 0.016) and non-Caucasian race (OR 2.42; P = 0.004) increased the risk of amputation on multivariate analysis. Osteomyelitis (P = 0.0371) and gangrene (P < 0.001) are independent risk factors for amputation. Across all three hospitals, 42.3% of patients were treated by amputation (6.8% private, 12% public and 23.5% VA; P < 0.001).

Conclusion

In a single triumvirate health care system where the patient population is stratified primarily by insurance, VA patients have significantly higher amputation rates compared with patients at adjacent private and public hospitals. The VA patients are largely racial minorities with advanced DFU progression to gangrenous ulcers.

摘要

背景

虽然有关糖尿病足溃疡治疗结果的差异已被详细描述,但很少有研究能够明确鉴别糖尿病足愈合与截肢率的危险因素。在一个独特的可以为城市中的公众、私人以及退伍军人患者提供服务的学术中心里,我们调查了不同治疗结果的截肢和治愈率以及具体危险因素。

方法

在三所地理位置相邻但各自独立的公立、私立和退伍军人管理局医院中进行了一项回顾性的调查表研究,调查对象为新诊断足部溃疡的糖尿病患者。评估了伤口愈合与下肢截肢的结果。

结果

在这三所医院中,有234名患者符合入选标准。与在私立及公立医院就诊的患者相比,在退伍军人管理局医院就诊的患者年龄较大(平均72.5岁;P < 0.001),且坏疽性溃疡的发病率更高(平均为14.1%;P < 0.001)。在公立医院就诊的患者大部分为西班牙裔(平均54%;P < 0.001),糖尿病病程更短(平均12.8年;P = 0.02),但是与在退伍军人管理局医院以及私立医院就诊的患者相比血糖控制更差(P ≤ 0.001)。经过多因素分析后发现先前的截肢术(优势比[OR]为1.97;P = 0.016)与非高加索人种(OR为2.42;P = 0.004)可增加截肢的风险。骨髓炎(P = 0.0371)与坏疽(P < 0.001)是截肢的独立危险因素。在所有三所医院中,有42.3%的患者接受了截肢手术(私立医院6.8%,公立医院12%,退伍军人管理局医院23.5%;P < 0.001)。

结论

在一个主要根据保险来区分患者人群的三驾马车式的卫生系统中,在退伍军人管理局医院就诊的患者与在邻近的私立以及公立医院就诊的患者相比截肢率明显更高。在退伍军人管理局医院就诊的患者主要是少数民族裔,且更容易从之前的糖尿病足溃疡进展为坏疽性溃疡。

Significant findings of the study: Insurance status is an independent predictor of disparate amputation outcomes of diabetic foot ulcer (DFU) patients.

What this study adds: Identification of modifiable risk factors to improve limb salvage by decreasing the delay in presentation for treatment of a DFU in high-risk groups.

Introduction

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

Diabetes is a significant and rapidly growing global problem that affects 180 million people worldwide. The Centers for Disease Control predicts that diabetes will escalate to affect 330 million people in the year 2030.[1, 2] In the US, 25.8 million people suffer from diabetes, with a lifetime risk of developing a diabetic foot ulcer (DFU) reportedly between 9.1% and 25%.[3, 4] Despite advances in wound care and evidence-based treatment protocols, almost half of all DFUs fail to heal and annual lower extremity amputation rates have remained steady at approximately 85 000.[5, 6] The development of a DFU is a sentinel event in the pathway to lower extremity amputation and increases the risk by almost sixfold.[7-9] In fact, complications of DFUs precede up to 85% of lower extremity amputations, making them the number one cause of non-traumatic limb amputations in the Western world.[10] Over half the patients who develop a unilateral foot lesion will subsequently develop a contralateral foot lesion and one-third of these patients will require contralateral amputations.[11]

Major amputations (above the malleolus) result in disability and diminished quality of life, increased morbidity and mortality, and longer hospital stays.[12] Alarmingly, the 5-year mortality rate after DFU-related amputation is 69%.[10] Furthermore, the cost of DFU-related care is increasing steadily. In the US, of the 116 billion healthcare dollars spent each year on diabetic patients, nearly one-third is spent on DFU treatment.[13] Hospitalizations and amputations account for a significant portion of the expenditure, and it is estimated that each amputation costs US$38 077.[13, 14]

The extent of the problem is particularly marked in ethnic minorities, low socioeconomic status groups, and the under- or uninsured.[15] Although African Americans and Hispanics represent a combined 28.7% of the US population, they have a threefold higher incidence of diabetes compared with non-Hispanic White Americans.[16, 17] Consequently, the amputation rates are disproportionately higher in African Americans and Hispanics, with an incidence rate that is 150–240-fold that of non-Hispanic Whites. However, studies on specific risk factors in these minority groups that contribute to these disparate amputation rates are lacking.

Our academic center consists of three independent tertiary care hospitals, namely a private, public, and VA hospital, within a 10-block radius that treat New York City's diverse population. Given that transport access to all three facilities is equivalent, the racial and socioeconomic makeup of the patients at each hospital is defined primarily by their insurance. The same physicians and residents provide care at each institution, suggesting that the standard of care as it is applied to patients with DFUs is essentially the same. Considering the healthcare providers, medical resources, access to care, and treatment options at all three hospitals as independent variables, we hypothesized that amputation rates would vary according to health insurance. Furthermore, we hypothesized that lower socioeconomic and minority patients with public insurance and Veterans benefits will have significantly higher DFU-related amputation rates than patients at the private hospital. Finally, we aimed to identify differences in amputation risk factors in the three patient populations presenting for DFU treatment.

Methods

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

Subjects

A retrospective chart review of patients presenting with a DFU at the three New York University teaching hospitals in 2009 was conducted under an Institutional Review Board-approved protocol (S12-00540). Criteria for inclusion were patients with a diagnosis of type 2 diabetes and a break in the skin of the foot documented as an ulcer. International Classification of Diseases (ICD-9) and Current Procedural Terminology (CPT) codes[18] were used to identify patients with diabetes, foot ulcers, and lower extremity amputations (Table 1). Charts were then reviewed manually for confirmation of diabetes and a new foot ulcer. All clinical data for patients that met the inclusion criteria were searched for 25 variables, including: (i) demographic information (age, sex, race, body mass index [BMI], insurance plan, and insurance status [Medicare, Medicaid, private, uninsured]); (ii) medical history (coronary artery disease [CAD], hypertension [HTN], peripheral arterial disease [PAD], chronic renal impairment and end-stage renal disease [CRI/ESRD], prior lower extremity amputation [either major or minor], active smoker); (iii) laboratory values at presentation (i.e. white blood cell [WBC] count, lipid panel, HbA1c, and albumin); and (iv) wound characteristics (initial and final wound area, and the presence of osteomyelitis and gangrene). Healing, defined as documented skin closure at patient visit, lower extremity amputation (LEA), level of amputation (major: above the malleolus; minor: below the malleolus) and time-to-amputation in days were recorded as outcomes for analysis.

Table 1. International classification of diseases (ICD-9) and current procedural terminology (CPT) codes[18]
ConditionCodes
Diabetes250.xx
Open wound of lower extremity250.8x, 707.x, 890.x, 440.23, 454.0, 250.8x
AmputationV49.70-v49.76, 84.11–84.18 27295, 27598, 27880, 27881, 27882, 27884, 27886, 27888, 27889, 28800, 28805, 28810, 28820, 28825
Peripheral arterial disease250.70, 250.71, 443.9, 459.81

Setting

The private, public and VA hospitals (New York University [NYU] Langone Medical Center, Bellevue Hospital and VA New York [NY] Harbor Hospital, respectively) in the present study are part of a single academic medical center served by NYU Medical School. The three hospitals are in the same geographic location, spanning a 10-block radius, with equivalent access via public and private transportation. All patients are treated by the same physicians and residents who provide care at all three institutions, allowing for uniformity of standard of care as it is applied to patients with DFUs.

Statistical analysis

Descriptive and comparative univariate analyses between the three hospital groups were performed using the Chi-squared test for categorical variables and ANOVA for continuous variables. The Mantel–Haenszel test was used to compare healing and amputation outcomes while controlling for hospital type. Multivariate analyses were conducted using Cox regression to analyze independent risk factors relative to time-to-amputation, whereas multiple logistic regression was used to identify independent predictors for healing and amputation. Models were selected using stepwise procedures with differences in the likelihood ratios as the criteria for model selection. All reported P-values are two-sided and P < 0.05 was considered significant. Analyses were performed using IBM SPSS Statistics for Windows, Version 19.0 (IBM Corporation, Armonk, NY, USA) and SAS 9.2 (SAS Institute, Cary, NC, USA).

Results

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

Patient demographics

In all, 850 patients were identified from a computer-generated data warehouse search of ICD-9 codes. After manual chart review, 616 patients did not meet the inclusion criteria and were excluded from analysis (Fig. 1). The mean age of all DFU patients was 64.8 years (Table 2). The VA hospital had significantly older patients, with a mean age of 72.5 years, compared with both the public (mean age 58.7 years) and private (mean age 66.9 years) hospitals (P < 0.001). Most DFU patients were men (75.6%), whereas all the VA DFU patients were male; this differed significantly from the other two hospitals (P < 0.001). Patients in the private hospital were predominantly Caucasian (70%), whereas the VA and public hospitals had a large African American population (49% and 27.2%, respectively; P = 0.005). Patients at the public hospital were mostly Hispanic (54%) compared with the public and VA hospitals, which each ≤10% Hispanic patients (P < 0.001). Medicaid and Medicare insurance plans accounted for 51.7% of non-VA patients. Patients without any insurance presented solely to the public hospital (P < 0.001).

figure

Figure 1. Results of a computer-run International Classification of Diseases (ICD-9) and Current Procedural Terminology (CPT) codes[18] search and characteristics of patients excluded from the study. In all, 850 subjects were identified as being diabetic and having a diabetic foot wound in all three hospital systems. Of the 476 subjects at the public hospital, 406 were excluded from analysis because they had peripheral arterial disease (PAD) without diabetes or an ulcer, diabetes without an ulcer, or an ulcer without diabetes. In the private hospital, 207 of 310 subjects were excluded because they did not have both diabetes and an ulcer in 2009. In the Veterans Administration (VA) hospital system, only three of 64 subjects were excluded from analysis.

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Table 2. Patient baseline characteristics according to hospital type
 TotalHospitalP-value (χ2, ANOVA)
PrivatePublicVA
  1. Unless indicated otherwise, data are the mean ± SD.

  2. VA, Veterans Administration; CRI/ESRD, Chronic renal insufficiency/end-stage renal disease; WBC, white blood cell; LDL, low-density lipoprotein; HDL, high-density lipoprotein.

n (%)2347010361 
Sex (% male)75.665.768.0100<0.001
Age (years)64.8 ± 14.166.9 ± 14.558.73 ± 13.272.49 ± 10.2<0.001
Race (%)    0.005
Caucasian62.4706746
African American30.318.527.249
Asian2.64.32.90
Other4.77.12.95
Ethnicity (%)    <0.001
Non-Hispanic72904695.1
Hispanic2810544.9
Diabetes duration (years)14.3 ± 9.816.9 ± 11.0512.8 ± 8.4513.9 ± 9.850.020
Current smoker (%)20.95.110.75.10.507
Prior amputation30.39.8310.79.830.168
Coronary artery disease (%)42.717.114.111.50.004
Hypertension (%)87.623.939.723.90.067
Peripheral arterial disease (%)52.615.820.516.20.151
CRI/ESRD(%)36.812.414.110.30.403
Stroke (%)13.42.995.984.270.555
Body Mass Index (kg/m2)28.3 ± 6.528.0 ± 7.729.2 ± 5.827.4 ± 6.30.209
Insurance (%)    <0.001
Medicare25.618.86.80
Medicaid26.13.023.10
Private15.88.17.70
VA26.10026.1
Uninsured6.4106.410
WBC (×109 cells/L)9.5 ± 4.310.0 ± 3.99.6 ± 4.78.7 ± 3.70.180
Albumin (mg/dL)3.8 ± 0.73.34 ± 0.633.97 ± 0.643.83 ± 0.58<0.001
Total cholesterol (mg/dL)155.8 ± 51.6146.4 ± 27.7167.2 ± 67.8147.2 ± 35.30.010
HDL (mg/dL)41.9 ± 14.136.8 ± 11.945.3 ± 15.941.9 ± 11.4<0.001
LDL (mg/dL)84.3 ± 29.479.2 ± 22.491.3 ± 33.778.4 ± 26.40.005
HbA1c (%)*8.08 ± 64.87 ± 539.1 ± 767.6 ± 59.6<0.001
Wound area (cm2)6.88 ± 15.811.1 ± 19.92.88 ± 5.098.74 ± 20.350.002
Wound area >5 cm2 (%)26.112.07.36.80.003
Osteomyelitis (%)33.812.412.09.40.137
Gangrene (%)31.68.19.414.1<0.001
Amputation (%)42.36.812.023.5<0.001
Minor amputation (%)34.24.79.819.7<0.001
Time-to-amputation (days)24.8 ± 56.513.4 ± 37.914.8 ± 51.554.8 ± 70.60.001
Healed (%)17.13.8511.51.710.003

Comorbidities

A history of prior amputation, HTN, CRI/ESRD, and/or stroke did not differ significantly across the three patient groups (Table 2). At the time of presentation for DFU treatment, 20.9% of patients were active smokers and 52.6% had a diagnosis of lower extremity PAD, and there were no significant differences among the three hospital groups. Coronary artery disease was present in 42.7% of patients, with most of the DFU patients with CAD presenting to the private hospital (17%; P < 0.004). Most patients were overweight, with an overall mean BMI of 28.3 ± 6.5 kg/m2; patients at the public hospital were the heaviest patients, with a mean BMI of 29.2 ± 5.8 kg/m2. However, this did not differ significantly from mean BMI for patients at the VA and private hospitals (P = 0.209, ANOVA).

Public hospital patients were more poorly controlled diabetic, as evidenced by a mean HbA1c of 9.1% (76 mmol/mol), whereas the private and VA patients had better glycemic control with mean HbA1c values of 7% (53 mmol/mol) and 7.6% (59.6 mmol/mol), respectively (P < 0.001, ANOVA). Cholesterol and lipid control across all three patient groups was optimal, with mean total cholesterol of 155.8 mg/dL, low-density lipoprotein 84.3 mg/dL, and high-density lipoprotein 41.9 mg/dL, but the public hospital patients also had more elevated lipid panels compared with the private and VA hospital patients (P = 0.01, ANOVA). Malnutrition, defined as a serum albumin level <3.5 g/dL, was present in the private hospital patients (mean albumin levels 3.34 g/dL) compared with the other two hospitals, where patients’ albumin levels were within normal limits (P < 0.001, ANOVA).

Wound characteristics

The overall mean wound area at initial presentation was 6.88 cm2. Patients at the private hospital had the largest wounds (mean area 11.1 cm2), whereas patients at the public hospital had the smallest wounds (2.88 cm2; P = 0.002). The proportion of patients with a wound area >5 cm2 was 26.1%, with almost half these patients from the private hospital (Table 2). Osteomyelitis was present in 33.8% of wounds, but there was no significant difference among the three groups (P = 0.137). Of all the wounds, 31.6% presented with gangrene and 45% of these gangrenous wounds were in VA patients (P < 0.001).

Amputation

Of all the patients, 42.3% had a lower extremity amputation, of which 81% were minor (Table 2). There was a significant difference in amputation rates among the three hospitals, with the highest rate at the VA hospital (23.5%), 12% at the public hospital, and the lowest rate at the private hospital (6.8%; P < 0.001). However, the VA hospital had the longest time from presentation to amputation (mean 54.8 days), whereas the private and public hospitals had similar mean time-to-event (13.4 and 14.8 days, respectively; P = 0.001).

When controlling for type of hospital, osteomyelitis and gangrene were the only significant risk factors for amputation on univariate analysis (Table 3). In multivariate analysis, male gender (P = 0.002), osteomyelitis (P = 0.0371), and gangrene (P < 0.001) were independent predictors of amputation (Table 4). In Cox's proportional hazards analysis including all variables stratified by hospital type, prior amputation (odds ratio [OR] 1.97; P = 0.016), non-Caucasian race (OR 2.42; P = 0.004), and an elevated WBC count (OR 1.17; P < 0.001) increased the risk of amputation. Conversely, a history of CAD (OR 0.48; P = 0.028), diabetes for >10 years (OR 0.51; P = 0.019), and stroke (OR 0.27; P < 0.001) decreased the risk of amputation by 0.48- and 0.51-fold, respectively (Table 5).

Table 3. Results of Cox's regression model for risk factors for amputation stratified according to hospital type
Model variablesRR (95%CI)P-value
  1. RR, relative risk; CI, confidence interval; BMI, body mass index; WBC, white blood cell; HDL, high-density lipoprotein.

Male gender1.51 (0.58–3.91)0.398
Age0.98 (0.951–1.01)0.107
Ethnicity0.87 (0.31–2.41)0.789
Non-Caucasian race2.42 (1.32–4.43)0.004
Current smoker0.78 (0.41–1.50)0.459
Prior amputation1.97 (1.13–3.41)0.016
Coronary artery disease0.48 (0.25–0.93)0.028
Hypertension0.90 (0.36–2.25)0.820
Renal failure0.99 (0.55–1.79)0.983
Peripheral arterial disease0.72 (0.37–1.41)0.334
Stroke0.27 (0.12–0.60)<0.001
BMI0.95 (0.91–0.99)0.039
Albumin1.82 (1.09–3.02)0.022
WBC1.17 (1.09–1.26)0.000
HDL1.02 (0.99–1.05)0.068
HbA1c1.11 (0.97–1.27)0.148
Osteomyelitis1.14 (0.66–1.97)0.630
Gangrene0.67 (0.40–1.13)0.134
Wound area >5 cm21.08 (0.56–2.08)0.818
Duration of diabetes >10 years0.51 (0.29–0.89)0.019
Table 4. Results of multivariate model of independent predictors of healing and amputation
Model variablesHealingP-valueAmputationP-value
  1. Data show the odds ratio, with 95% confidence intervals in parentheses.

  2. VA, Veterans Administration.

Wound area <5 cm25.13 (1.45–18.20)0.011  
Gender (male)  5.21 (2.21–12.3)0.0002
Osteomyelitis (absence)3.39 (1.30–8.83)0.0130.50 (0.26–0.96)0.0371
Gangrene (absence)  0.11 (0.06–0.22)<0.0010
Insurance (VA)0.17 (0.03–0.94)0.030  
Table 5. Predictors of healing and amputation controlling for hospital type
 Amputees (%)Non-amputees (%)P-value, χ2mhHealed (%)Non-healed (%)P-value, χ2mh
  1. χ2mh, data are mean values with significance for P-values < 0.05.

Gender (male)89.965.20.14365.077.80.478
Duration diabetes >10 years56.648.80.24532.556.20.013
Race (Caucasian)55.667.40.91965.061.90.917
Ethnicity (Hispanic)16.237.00.23545.024.70.477
Active smoking24.218.50.21517.523.20.048
Prior amputation35.426.70.54220.032.50.233
Coronary artery disease44.441.50.72745.042.30.364
Hypertension91.984.40.34887.587.60.891
Renal failure37.436.30.93027.538.70.361
Peripheral arterial disease61.245.90.12542.554.60.406
Stroke14.112.60.97012.513.40.885
Osteomyelitis43.426.70.00415.037.60.016
Gangrene57.612.6<0.00120.034.00.341
Wound area >5 cm222.228.90.2627.529.90.015

Healing

Of patients with wounds, 17.1% healed; 67.2% of these were patients at the public hospital (Table 2). The lowest healing rate (1.71%) was at the VA hospital, followed closely by the private hospital (3.85% of all wounds; P = 0.003). When comparing healed and non-healed patients controlling for hospital type, patients with diabetes for >10 years (P = 0.013) and who were actively smoking (P = 0.048) were non-healers (Table 5). Furthermore, wounds that were >5 cm2 (P = 0.015) and had osteomyelitis (P = 0.016) were also associated with non-healing.

In multivariate analysis, wound area <5 cm2 (OR 5.13; P = 0.011) and the absence of osteomyelitis (OR 3.39; P = 0.013) were independent predictors of a healed outcome, whereas having VA insurance (OR 0.17; P = 0.03) was a significant predictor of a non-healed outcome (Table 4).

Discussion

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

In the present study we demonstrated that despite a similar standard of care at three institutions in a single academic medical center, DFU patients at the VA and public hospitals have a significantly increased amputation rate compared with DFU patients at the private hospital. Certain features of these three hospitals empower the study of amputation disparities among the three populations. All three hospitals are part of a single academic institution; the same medical faculty practices the same standard of care at all three hospitals. In addition, the close proximity of all three hospitals (they are only separated by three city blocks) minimizes or eliminates location-based access to care barriers that may affect the timeliness of presentation or ability to return for follow-up visits. Therefore, we infer that patient-specific risk factors explain the disparate amputation rates across these institutions.

The VA hospital, with the highest amputation rate (23.5%), has a much older, predominantly African American population. This is consistent with prior studies that have demonstrated that elderly patients and African Americans with DFUs are at higher risk of amputation.[19, 20] Furthermore, at initial presentation for treatment, these patients have more advanced DFUs, as evidenced by the higher incidence of gangrenous ulcers in this population. Several studies have demonstrated that gangrene is a significant risk factor for LEA,[20-22] which was also an independent risk factor for LEA in multivariate analysis in the present study. Most preventative care for DFUs at the VA hospital is provided by podiatrists who refer patients to subspecialty services, such as vascular surgery and endocrinology for revascularization and glycemic control, respectively, or perform amputation when limb or digit salvage options are exhausted. However, despite attention to care, our data suggest that at initial presentation, DFU patients at the VA hospital present at an advanced degree of DFU progression.

The public hospital, with an amputation rate of 12%, had a largely Hispanic population with poorly controlled diabetics, as evidenced by a higher mean HbA1c (9.1%; 76 mmol/mol). Interestingly, although these patients were the most poorly controlled diabetics, they had the highest healing rate, over threefold greater than patients with private insurance, who were more tightly controlled diabetics (mean HbA1c 7%; 53 mmol/mol). The significance of maintaining tight HbA1c control to promote wound healing has been contentious and our data contribute to the controversy. A recent study by Christman et al.[23] was the first to demonstrate a strong correlation between wound healing and glycemic control, in that for every 1% increase in HbA1c there was a concomitant decrease in wound area healing rate.[23] However, other studies have found either no association between glycemic control and DFU healing or only reported a trend.[24-26] In the present study, there is a negative trend between HbA1c and healing, and no association between HbA1c and amputation. Further investigations are currently underway in a prospective randomized trial to determine whether glycemic control will improve outcomes of DFU, particularly amputation.

Private hospital patients had the lowest amputation rates, but the shortest time to amputation (mean 13.4 days; P = 0.001), suggesting that the amputees presented with unsalvageable limbs that necessitated amputation. These patients were predominantly Caucasian, malnourished (as evidenced by low mean serum albumin levels [3.34 g/dL]), and had the largest mean wound area at presentation (11.1 cm2). Although the initial wound area was not a significant risk factor for amputation, it was an independent predictor of healing, such that DFUs with an area <5 cm2 were fivefold more likely to heal (OR 5.13; P = 0.011). This is consistent with prior studies that have shown that larger wound areas are associated with non-healing and an increased time to healing.[27, 28] Malnutrition was also a significant risk factor for amputation (OR 1.83; P = 0.022) in this group. Although malnutrition has been associated with poor wound healing outcomes, no prior studies have shown a direct correlation with amputation risk.[29, 30]

Limitations of the present study include a small sample size and relatively short study period. There were fewer patients from the VA hospital (n = 61) than in the private and public hospitals (n = 103 and 70, respectively). Despite this discrepancy and after controlling for hospital type, male gender, osteomyelitis, and gangrene were significant independent risk factors for lower extremity amputation. This confirms the results of prior studies that have shown osteomyelitis and gangrene are significant risk factors for amputation.[20-22, 31, 32] Importantly, the results of the present study highlight a disparity in the initial presentation of DFUs, with more advanced DFUs in the VA and public hospitals suggesting obstacles to appropriate health care. Several studies comparing VA and non-VA institutions on quality of care for diabetes have shown that the VA patients have higher rates of foot examinations, diabetes education, and patient satisfaction, as well as tighter glucose control.[33-36] However, none of these studies focused on patients who had already developed a foot ulcer, who, as evidenced by the present study, have a markedly increased rate of amputation.

Acknowledgement

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

This study was supported by a grant from the Agency for Healthcare Research and Quality (R01 HS019218-01).

Disclosure

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References

The authors have no financial conflict of interest to declare.

References

  1. Top of page
  2. Abstract摘要
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. Disclosure
  9. References
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