Journal of Vascular Surgery
Volume 47, Issue 5 , Pages 1001-1007, May 2008

A census-based analysis of racial disparities in lower extremity amputation rates in Northern Illinois, 1987-2004

  • Joe Feinglass, PhD

      Affiliations

    • Division of General Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill
    • Corresponding Author InformationReprint requests: Joe Feinglass, PhD, Northwestern University Feinberg School of Medicine, General Internal Medicine, 676 N St Clair #200, Chicago, IL 60611.
    • ,
  • Shabir Abadin, MD, MPH

      Affiliations

    • Northwestern University Masters in Public Health Degree Program, Chicago, Ill.
    • ,
  • Jason Thompson, BA

      Affiliations

    • Division of General Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill
    • ,
  • William H. Pearce, MD

      Affiliations

    • Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, Chicago, Ill

Received 28 August 2007; accepted 13 November 2007. published online 25 March 2008.

Article Outline

Background

Given improvements in care for peripheral vascular disease and diabetes over the last two decades, it was of interest whether racial disparities in lower extremity amputation rates had changed.

Methods

Hospital data for 18 years (1987-2004) were used to compute above, below, and through foot amputation rates for over eight million people living in the Chicago metropolitan area. Three areas were created from zip code level census data. Differences in amputation rates were compared between residents of zip code areas that were >50% African American, 10% to 50% African American, or <10% African American.

Results

The largely African American area of the South and West sides of Chicago, with less than 15% of the area population, accounted for 27% of all amputation discharges (n = 33,775) over the 18 years. For all residents of northern Illinois, major (above and below knee) amputation rates declined to 17 per 100,000 residents over the last decade, and both inpatient mortality and length of stay fell throughout the period. However, residents of largely African American zip codes had over five times higher per capita amputation rates than residents of primarily white zip codes.

Conclusions

Racial disparities have remained remarkably constant, despite progress in reducing the overall major amputation rate in northern Illinois. Addressing these disparities will require that low income, medically complex patients at risk of limb loss receive timelier, high performance care, combined with community-based public health and preventive medicine interventions that address the social determinants of health.

 

Racial and ethnic disparities in lower extremity amputation rates have been well established by numerous population-based studies.1, 2, 3, 4, 5, 6, 7 Compared with non-Hispanic whites, African Americans have between two to four times the likelihood of undergoing a major (above or below knee) amputation, and this disparity increases among the oldest of the old.1 While African Americans accounted for about 12% of the US population in 1996, they accounted for approximately 25% of all nontraumatic amputations in that year.8 While it might be thought that the greater amputation risk for African Americans is due to a higher prevalence of diabetes,9 racial disparities exist for both patients with and without diabetes and the nondiabetic racial disparity in amputation rates may even be larger.2, 3, 6, 10, 11

There is a broad consensus that aggressive primary care and preventive interventions such as diabetes foot care programs can reduce amputation incidence, and that many amputations are preventable.12, 13, 14, 15, 16 Given the significant recent attention to reducing racial disparities, combined with numerous quality improvement initiatives for patients with diabetes, it was of interest to document whether racial disparities in amputation rates have been reduced over the last two decades. Epidemiologic monitoring of amputation rates is of particular importance given the expected increase in diabetes prevalence associated with the obesity epidemic.

This study presents an 18-year overview of hospital administrative discharge data for amputation procedures among residents of the nine counties of Northern Illinois, which encompass over eight million people living in the greater Chicago metropolitan area. The study uses a community area perspective to describe differences in amputation rates. Three large areas are profiled based on zip code level census data, which allow us to track differences in amputation rates for residents of largely African American, more integrated, or largely white populations. We present rates by amputation levels (above knee, below knee, and through foot), and review differences in inpatient mortality and ICD-9 coded diabetes prevalence. Results provide the longest time series examination of amputation rates for any large area of the United States and have important implications for strategies to reduce racial disparities.

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Methods 

Hospital discharge data 

The study was ruled exempt by the Northwestern University Institutional Review Board. De-identified data for all discharges of residents living in nine county northern Illinois (Cook, DuPage, Grundy, Kane, Kankakee, Kendall, Lake, McHenry, and Will counties), who underwent an amputation procedure at any nonfederal hospital in Illinois, were obtained from the Illinois Department of Public Health (IDPH) for the years 1987-2004. Patients were included in the sample if their zip code was in the nine-county area, regardless of where in Illinois the hospital was located. Discharges were selected for any listed ICD-9 procedure codes for through foot (84.12), below knee (84.15), and above knee (84.17) amputation (toe amputations only were excluded). Admissions with multiple amputation procedures were assigned to the most proximal level to compute level-specific rates. ICD-9 diagnosis codes were used to determine diabetes prevalence according to the Elixhauser comorbidity codes17 and discharge status was used to determine inpatient mortality.

To focus exclusively on nontraumatic amputation, patients under age 35, or patients with ICD-9 coded traumatic or cancer related amputation procedures were excluded. Additionally, excluded were a very small number of patients undergoing amputations in conjunction with coronary bypass surgery, aortic aneurysm repair, or who had codes for disarticulation of the ankle, knee, or hip (rarely used for nontraumatic amputations). Because individual patients could not be identified from IDPH discharge data, amputations that occurred for the same patient in two separate hospital stays are counted as separate admissions. The IDPH data do not include approximately 5% of all amputation procedures performed annually at the three Chicago-area VA hospitals for primarily male veterans.18

Zip code level census demographic data 

Census-based data for approximately 300 zip codes for 1990 and 2000 were used to provide population denominators for northern Illinois amputation rates.19 Linear extrapolation was used to create annual zip code demographic estimates for the full period 1987-2004, which were then matched to IDPH discharge data numerators by patient origin zip code. Because there were some changes in zip codes between 1990 and 2000, a small number of discharges were matched exclusively to 33 zip codes that existed only in 1990 and 11 zip codes that only existed in 2000. Only 140 discharges (0.3%) in the final analysis file were missing zip code data and excluded.

Census data included total zip code populations for males and females and African American for eight age groups. To derive population denominator areas for comparing racial disparities in amputation rates, the number of African Americans in each zip code was divided by the total zip code population. Three contiguous areas were thus created based on zip codes with <10%, 11% to 50%, or >50% African American populations (Table I). These areas correspond to the very racially segregated South and West sides of Chicago with most zip codes having >80% African American populations (about 1.1 million residents in 2000), the inner ring of suburbs, and some areas of the North side of Chicago with racially and ethnically mixed populations (about 1.7 million residents in 2000), and the predominantly white Northwest and Southwest sides of Chicago and outlying suburban and exurban areas (about 5.4 million residents in 2000). The large Chicago-area Mexican American population is predominantly located in the 10% to 50% African American zip code area. The non-African American population in the >50% African American zip code area is about half Puerto Rican, Mexican, or Central American and about half white. Discharges between 1987 and 1995 were assigned to 1990 zip code status and discharges from 1996-2004 were assigned to 2000 zip code status thus reflecting some significant African American population shifts between 1990 and 2000. These methods produced more accurate population-based denominators than used in a previously published study of 1993-1997 northern Illinois vascular surgery and amputation rates.20, 21

Table I. 1990 and 2000 nine county Northern Illinois zip code census data by percentage African American population
1990 Census (295 zip codes)
African American population categoryEstimated total populationEstimated median household incomeEstimated mean African American population percentage
<10%4,956,077$53,8521.5%
11%-50% n1,629,930$37,99622.4%
>50%1,270,680$22,53280.2%
All zip codes7,856,687$48,66411.4%
2000 Census (318 zip codes)
African American population categoryEstimated total populationEstimated median household incomeEstimated mean African American population percentage
<10%5,387,613$63,6582.3%
11%-50%1,756,184$47,22928.1%
>50%1,067,565$30,28583.8%
All zip codes8,211,362$58,00913.4%

Computation and comparison of rates 

To account for shifts in population age over time, annual rates were directly age-standardized to the year 2000 population based on eight age groups (35 to 44, 45 to 49, 50 to 54, 55 to 59, 60 to 64, 65 to 69, 70 to 74, and 75 or older). Annual rates per 100,000 residents were computed for all three amputation levels for all northern Illinois residents, for men and women, and for each of the three racially defined zip code areas described above for each of the 18 years in the study period. The Mantel-Haenszel χ2 test for linear trends in proportions was used to test the significance of associations between year and differences in area amputation rates, as well as trends in inpatient mortality and diabetes prevalence.

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Results 

A total of 33,775 discharges included at least one through foot or major amputation of a northern Illinois resident, performed at 171 Illinois hospitals, during the 18-year study period. One third of all discharges were at hospitals with less than 50 amputations in the sample, including many Illinois hospitals that were at the border of or outside the nine-county area. Conversely, 45 hospitals had over 300 amputation discharges and eight hospitals had over 700 discharges during the 18 years.

Table II presents aggregate data for all 18 years by amputation level. There was a small male predominance (an underestimate given the lack of VA hospital data). Diabetes prevalence increased significantly, and mean age decreased at more distal levels of amputation. While the area with >50% African American population accounted for approximately 16% of the total northern Illinois population in 1990 and 13% in 2000, these residents accounted for almost 27% of all amputation discharges during the study period.

Table II. Lower extremity amputation by level, 1987-2004 (n = 33,775 discharges of Northern Illinois residents)
Above knee amputation (ICD-9 code 84.17) n = 13,241 (39.2%)Below knee amputation (ICD-9 code 84.15) n = 14,801 (43.8%)Through foot amputation (ICD-9 code 84.12) n = 5733 (17.0%)All procedures n = 33,775 (100%)
Men5764(43.5%)8259(55.8%)3703(64.6%)17,726(52.5%)
Women7477(56.5%)6542(44.2%)2030(35.4%)16,049(47.5%)
Mean age(y)75.5(SD=12.0)68.8(SD=12.8)64.9(SD=12.9)70.8(SD=13.2)
Diabetes6131(46.3%)10,293(69.5%)4607(80.4%)21,031(62.3%)
Inpatient mortality1439(10.9%)863(5.8%)142(2.5%)2444(7.2%)
African American zip code population >50%6050(45.7%)7471(50.5%)2889(50.4%)16,410(48.6%)
African American zip code population 11%-50%3476(26.3%)3439(23.2%)1376(24.0%)8291(24.5%)
African American zip code population <10%3715(28.1%)3891(26.3%)1468(25.6%)9074(26.9%)

When examining specific trends over the 18 years, it was of interest that the overall proportion of amputees with ICD-9 coded diabetes increased continuously. For patients undergoing major amputation, diabetes increased from only 46% in 1987 to 60% in 1995 and 68% by 2004 (P < .0001, data not shown). The proportion of amputees with diabetes was significantly lower among residents living in higher African American population areas at every level of amputation. Overall, 63.9% of amputees of largely white zip codes had diabetes coded, compared with only 59.8% among residents living in zip codes that were >50% African American (P < .0001), suggesting that racial disparities in amputation rates may be even larger among nondiabetics. ICD-9 coded gangrene remained stable and was coded for just under one-half of all patients; osteomyelitis codes more than doubled during the period to almost 20% of all amputations in 2004. Graft failure codes were present for only 1.1% of the sample.

Inpatient mortality rates and length of stay 

Inpatient mortality rates, which averaged from 10.9% for above knee to 2.5% for through foot amputations, fell dramatically throughout the period. When examining annual trends, above knee amputation was associated with a 15.1% mortality rate from 1987-1989 and fell throughout the study period to 7.9% in 2002-2004. Below knee amputation inpatient mortality fell from 6.8% in 1987-1989 to 3.9% in 2002-2004, while through foot amputation mortality declined from 4.8% in 1987-1989 to 1.4% in 2002-2004 (all P < .0001). Despite the overall decrease, mortality rates were consistently higher for areas with higher African American population throughout the study period. Summed across all 18 years, residents living in <10% African American zip codes had an overall 18-year inpatient mortality rate of 10.4% for above knee, 5.6% for below knee, and 1.9% for through foot amputation, compared with rates of 10.9%, 6.2%, and 3.1%, respectively, among residents of areas with >50% African American population (P < .0001).

However, this decline in inpatient mortality was highly correlated with a decline in average length of stay (ALOS). For instance, ALOS for through foot amputation fell from over 22 days in 1987 to about 12 days in 2004; ALOS for above knee amputation declined from over 24 days to 15 days during the same period. Thus, it remains unknown whether the decline in inpatient mortality reflects a true decline in 30-day mortality. Moreover, ALOS for patients from largely African American zip codes was consistently higher than for other amputees. The cumulative difference over the study period in ALOS between largely African American and largely white areas ranged from 3.8 days for above knee amputees to 2.3 days for through foot amputees. It is thus unclear whether the disparities in inpatient mortality reflect true death rate differences, or merely differences among patients who die at home or in nursing facilities instead of the hospital.

Amputation rate comparisons 

Fig 1 presents the overall major amputation rate (above and below knee), including male and female rates, across the 18-year study period. After a peak at 24 per 100,000 northern Illinois residents in 1996, the major amputation rate declined to 17 per 100,000 in 2004. Sex differences gradually narrowed. Fig 2 presents amputation rates by level. The largest decline was for above knee procedures, from a peak rate of 11 per 100,000 in 1996 to 7 per 100,000 in 2004. Through foot amputation rates increased during the 18 years, from a 1987 rate of 2 per 100,000 to a peak of 6 per 100,000 in 1996, then declining to 4 per 100,000 in 2004.

Fig 3 presents the major amputation rates for the three zip code defined areas. The high African American population area had rates over five times higher than the primarily white population area, while residents of the mixed area (which includes a large Hispanic population and most of the Chicago-area Spanish speaking population) had rates over 60% higher. Major amputation rates for residents of the primarily white population area declined from 14 per 100,000 in 1987 to 12 per 100,000 in 2004. By comparison, residents of zip codes with >50% African American population had major amputation rates of 59 per 100,000 in 1987, peaking at 84 per 100,000 in 1996, and declining to 65 per 100,000 in 2004. The test for whether major amputation rate disparities were growing or shrinking between high and low African American populations was not significant (P = .23) due to the mid-1990s peak and subsequent declines.

Through foot amputation rate disparities increased between 1987 and 2004. The difference in rates of through foot amputation procedures between residents of primarily white zip codes and residents of primarily African American zip codes grew over the study period. The through foot amputation rate among residents of primarily white zip codes grew from 2 per 100,000 persons in 1987 to 3 per 100,000 persons in 2004. During the same period, rates among residents of largely African American zip codes increased from 7 per 100,000 in 1987 to 18 per 100,000 in 2004.

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Discussion 

Progress in major amputation rate trends 

Earlier population-based studies of the US amputation rate, which reviewed data from the 1980s through the mid-1990s, raised concerns about what were increasing nontraumatic lower extremity amputation rates.8, 22 Looking ahead from the late 1990s, it was then assumed that the overall US amputation rate would continue to increase, given increases in diabetes prevalence and the known two- to threefold increased prevalence of peripheral arterial disease among diabetics.23, 24 In addition, amputation rates could potentially increase due to a generally aging population of older survivors with diabetes, coronary artery and kidney disease, many susceptible to hospitalization for peripheral arterial disease complications.25

The overall major amputation rate data presented here for northern Illinois residents present a much more optimistic picture, with an evident downturn in overall amputation rates after a peak in 1996. These regional data mirror national trends from the Agency for Healthcare Research and Quality (AHRQ) Nationwide Inpatient Sample, which reflects nonfederal hospital discharges from over two dozen states.26 Current on-line AHRQ estimates for US major amputation procedures (ICD-9 codes 84.15, 84.17) rose from 65,274 in 1993 to a peak of 74,779 in 1998, and have since declined dramatically to 67,906 in 2004 and only 60,249 in 2005. Through foot amputation procedures have also declined in recent years, from an estimated 14,337 in 1993 to a peak of 18,509 in 1998, then falling to 15,478 by 2005. One study of AHRQ data estimates that there was an over 20% reduction in major amputation rates nationally, from 1998-2003 to about 21 per 100,000 population in 2003.27 Similar improvement in population-based amputation rates from a late 1990 peak has also been reported in England.28

Reasons for the overall downturn in major amputation rates remain highly speculative, but several factors are promising areas for future research. First is the overall improvement in diabetes management in the last 10 years, coinciding with the development of diabetes care evaluation measures, including heightened delivery system efforts to provide diabetic patients with regular foot and eye care, frequent blood sugar measurement to achieve tight control, and more aggressive treatment of hypertension. The large increase over time in the prevalence of ICD-9 coded diabetes among amputees found in northern Illinois may be at least partly the result of better diabetes diagnosis and treatment.

The late 1990s was also the era when statin drug use took off in the United States, with potentially large subsequent benefits for many patients with peripheral arterial disease.29, 30 Although overall smoking rates have not decreased sharply in recent years, it is possible that reductions in smoking prevalence that occurred in earlier decades may be responsible for some of the improvement in peripheral vascular disease progression in our current older population.31 Finally, it is possible that improved vascular surgery and angioplasty procedures (including the increase in lower extremity stent placement) are contributing to improved arterial patency and amputation-free survival times for revascularized patients.27

The persistence of racial disparities in amputation rates 

Despite overall progress, amputation rates remained hugely disproportionate among the over one million northern Illinois residents living in the largely African American South and West sides of Chicago. The higher amputation rate among residents of the racially mixed zip code area likely reflects amputations for the large Hispanic population living there, as well as African Americans, as opposed to the area's largely affluent or middle class whites who live in close proximity. These shockingly higher rates for areas with large minority populations underscore the limits of improvements in medical care when access to care differs. Amputation rates for the largely white population remained virtually unchanged over 18 years (Fig 3), while the fivefold higher trend among Chicago's minority populations drove overall rate fluctuations. While the ratio of above to below knee operations improved modestly over time for residents of largely African American zip codes, disparities in through foot procedures may have increased in recent years (data not shown). Amputation rates thus join the long list of racial disparities in Chicago's health and vital statistic indicators which have failed to improve over the last decade.32

What factors account for the maintenance of disparities in amputation rates over this long time period? One factor that may be compounding the magnitude of racial disparities in amputation procedures is more frequent re-amputation procedures experienced by African American patients. A multi-hospital medical record review study in Chicago found that racial disparities were as great for repeat as opposed to primary (incident) amputation procedures.33, 34 Medicare data indicate that 26% of all amputees in 1996 underwent a second amputation within a year; one-third also died within the year.35 Higher re-amputation rates may be part of the reason for racial disparities in total procedures and reflect potentially important rehabilitation, home health, end of life, and palliative care issues for amputees.35

Amputation disparities and the social determinants of health 

The magnitude of the disparities described here can only be explained by differences in social determinants of health, and reflect the disease burden frequently associated with the effects of low socioeconomic status, segregation, and concentrated neighborhood poverty.36 One example is provided by race and ethnicity differences in the trajectory of childhood and adolescent weight gain, which in part underlie disparities in diabetes prevalence, duration, and severity.37, 38 Diabetic control levels may differ by race. Among a diverse population with diabetes followed for a decade, HbA1c levels >7.5% were associated with a fivefold increase in the number of hospitalizations for peripheral arterial disease compared with diabetics with good glycemic control levels, at HbA1c < 6%.23 Studies of racial differences in diabetes quality of care indicate that disparities primarily result from minority patients lacking equal access to high performing providers, including easily navigable, culturally competent diabetes management and self-management programs.39, 40, 41

Population-based studies have found that current smokers have four times the likelihood of having peripheral arterial disease (diagnosed as ankle-brachial index < 0.90).23 Smoking prevalence follows a very strong socioeconomic gradient and is more prevalent among older men. While smokers' reported attempts to quit are similar across income and educational levels (at 40% to 50% of smokers), success in quitting is concentrated among the better off.42 In Chicago, a large household survey conducted in six Chicago community areas found a 39% smoking rate in one largely African American community, compared with an 18% smoking rate in a better off, largely white community area.43

In contrast, national survey data show that African Americans have a lower probability of smoking than whites.42 Research on racial disparities in mortality rates, and especially mortality rates among the older population, finds little evidence that smoking is a major factor contributing to mortality differences.44, 45, 46 Much more research is needed to assess the attributable risk of amputation associated with smoking, or whether amputation rate disparities are indeed linked to differences in smoking in the older population.

Limitations 

The IDPH hospital administrative data used in this study are severely limited by lack of individual patient identifiers, and by lack of any “matchable” death index identifiers indicating whether a given patient was alive in a given year. Thus, primary versus re-amputation rates are not ascertainable, and longitudinal amputation follow-up outcomes are not available. A further weakness is that amputations are not coded by which side they are performed on, leaving no record of whether repeat procedures are ipsilateral or contralateral amputations.

A further limitation of this study is the lack of patient race identifiers in the IDPH data. A small proportion of amputees from the largely African American area were undoubtedly Puerto Rican, Mexican, or other Latin American, and a few are white, but this should have only a very minimal effect on the rate ratios we have described. Having individual patient race at hospital registration would, in theory, be preferable, although many problems exist with uneven registration data.45 However, analyzing rates by geographic areas that concentrate large socioeconomic differences has the virtue of emphasizing simultaneously race and socioeconomic differences in procedure rates. In contrast, aggregating individual patient race identifiers into a single amputation rate numerator confounds data for individuals living in vastly different community environments. This study reflects the specific socioeconomic conditions of Chicago, where low income or poor whites are uncommon, and racial disparities exist across many aspects of health. It is thus likely that rather than race itself, socioeconomic inequality, including differential access to and quality of care, underlies most of the differences in amputation rates described here.45, 47

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Conclusion 

Racial disparities in cardiovascular disease risk are based on “primordial” differences in risk factors at every age.46, 48 Disparities in baseline risk are compounded by barriers to high quality care, such as unequal access to hospital wound care and vascular medicine or surgery facilities.21, 49 Profiling amputation rates provides a revealing indicator of regional disparities in health. This study illustrates one method for epidemiologic surveillance of ongoing efforts to reduce these disparities.

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Author contributions 


Conception and design: JF, WP

Analysis and interpretation: JF, WP

Data Collection: SA, JT

Writing the article: JF, SA

Critical revision of the article: JF

Final approval of the article: JF, SA, JT, WP

Statistical analysis: JF, JT

Obtaining funding: Not applicable

Overall Responsibility: JF

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References 

  1. Dillingham TR, Pezzin LE, Mackenzie EJ. Racial differences in the incidence of limb loss secondary to peripheral vascular disease: a population-based study. Arch Phys Med Rehabil. 2002;83:1252–1257
  2. Guadagnoli EAJ, Gibbons G, McNeil BJ, LaGerfo EA. The influence of race on the use of surgical procedures for treatment of peripheral vascular disease of the lower extremities. Arch Surg. 1995;130:381–386
  3. Huber TS, Wheeler KG, Cuddeback JK, Dame DA, Ozake CK, Flynn TC, et al. Impact of race on the treatment for peripheral arterial occlusive disease. WJ J Vasc Surg. 1999;30:417–426
  4. McBean AM. Differences by race in the rates of procedures performed in hospitals for Medicare beneficiaries. GM Health Care Financing Rev. 1994;15:77–89
  5. Mort EA, Epstein AM. Physician discretion and racial variation in the use of surgical procedures. WJ Arch Intern Med. 1994;154:761–767
  6. Tunis SR, Klag MJ, Steinberg EP. Variation in utilization of procedures for treatment of peripheral arterial disease. BE Arch Intern Med. 1993;153:991–998
  7. Lavery LL, Van Houtum W, Pugh JA, Harkles LB, Basu S. Variation in the incidence and proportion of diabetes-related amputations in minorities. AH Diabetes Care. 1996;19:48–52
  8. Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation and limb deficiency: epidemiology and recent trends in the United States. South Med J. 2002;95:875–883
  9. Cowie CC, Rust KF, Byrd-Holt DD, Eberhardt MS, Flegal KM, Engelgau MM, et al. Prevalence of diabetes and impaired fasting glucose in adults in the US population: National Health And Nutrition Examination Survey 1999-2002. Diabetes Care. 2006;29:1263–1268
  10. Collins TC, Henderson W, Khuri SF, Daley J. Lower extremity nontraumatic amputation among veterans with peripheral arterial disease: is race an independent factor?. JM Medical Care. 2002;40(Suppl):I-106–I-116
  11. Lavery LA, van Houtum WH, Ashry HR, Armstrong DG, Pugh JA. Diabetes-related lower-extremity amputations disproportionately affect Blacks and Mexican Americans. South Med J. 1999;92:593–599
  12. Apelqvist J, Larsson J. What is the most effective way to reduce incidence of amputation in the diabetic foot?. Diabetes Metab Res Rev. 2000;16(Suppl 1):S75–S83
  13. Mayfield JA, Reiber GE, Sanders LJ, Janisse D, Pogach LM. Preventive foot care in diabetes. Diabetes Care. 2004;27(Suppl 1):S63–S64
  14. Ollendorf DA, Kotsanos JG, Wishner WJ, Friedman M, Cooper T, Bittoni M, et al. Potential economic benefits of lower-extremity amputation prevention strategies in diabetes. Diabetes Care. 1998;21:1240–1245
  15. Philbin TM, Berlet GC, Lee TH. Lower-extremity amputations in association with diabetes mellitus. Foot Ankle Clin. 2006;11:791–804
  16. Ragnarson Tennvall G, Apelqvist J. Prevention of diabetes-related foot ulcers and amputations: a cost-utility analysis based on Markov model simulations. Diabetologia. 2001;44:2077–2087
  17. Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for use with administrative data. Med Care. 1998;36:8–27
  18. VHA. Lower Extremity Amputation & Ulcer Statistics. http://vaww.cf.webdev.va.gov/vhaamputationdata/index_process.cfm2007;Accessed 2/1/2007
  19. Bureau. USC. American Factfinder Decennial Census. http://factfinder.census.gov/home/saff/main.html?_lang=en2006;Accessed 11/14/2006
  20. Krieger N, Waterman P, Chen JT, Soobader MJ, Subramanian SV, Carson R. Zip code caveat: bias due to spatiotemporal mismatches between zip codes and US census-defined geographic areas--the Public Health Disparities Geocoding Project. Am J Public Health. 2002;92:1100–1102
  21. Feinglass J, Handel D, Martin GJ, Pearce WH. Peripheral bypass surgery and amputation: Northern Illinois demographics 1993-1997. KS Arch Surg. 2000;135:75–80
  22. Feinglass J, Brown JL, LoSasso A, Sohn MW, Manheim LM, Shah SJ, et al. Rates of lower-extremity amputation and arterial reconstruction in the United States, 1979 to 1996. Am J Public Health. 1999;89:1222–1227
  23. Selvin E, Erlinger TP. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 1999-2000. Circulation. 2004;110:738–743
  24. Wattanakit K, Folsom AR, Selvin E, Weatherley BD, Pankow JS, Brancati FL, et al. Risk factors for peripheral arterial disease incidence in persons with diabetes: the Atherosclerosis Risk in Communities (ARIC) Study. Atherosclerosis. 2005;180:389–397
  25. Bethel MA, Sloan FA, Belsky D, Feinglos MN. Longitudinal incidence and prevalence of adverse outcomes of diabetes mellitus in elderly patients. Arch Intern Med. 2007;167:921–927
  26. AHRQ. HCUPnet Nationwide Inpatient Sample. http://hcupnet.ahrq.gov/HCUPnet.jsp2007;Accessed 7/21/2007
  27. Nowygrod R, Egorova N, Greco G, Anderson P, Gelijns A, Moskowitz A, et al. Trends, complications, and mortality in peripheral vascular surgery. J Vasc Surg. 2006;43:205–216
  28. McCaslin JE, Hafez HM, Stansby G. Lower-limb revascularization and major amputation rates in England. Br J Surg. 2007;94:835–839
  29. Giri J, McDermott MM, Greenland P, Guralnik JM, Criqui MH, Liu K, et al. Statin use and functional decline in patients with and without peripheral arterial disease. J Am Coll Cardiol. 2006;47:998–1004
  30. Heart Protection Study Collaborative G. Randomized trial of the effects of cholesterol-lowering with simvastatin on peripheral vascular and other major vascular outcomes in 20,536 people with peripheral arterial disease and other high-risk conditions. J Vasc Surg. 2007;45:645–654
  31. Vollset SE, Tverdal A, Gjessing HK. Smoking and deaths between 40 and 70 years of age in women and men. Ann Intern Med. 2006;144:381–389
  32. Margellos H, Silva A, Whitman S. Comparison of health status indicators in Chicago: are Black-White disparities worsening?. Am J Public Health. 2004;94:116–121
  33. Feinglass J, Rucker-Whitaker C, Lindquist L, McCarthy WJ, Pearce WH. Racial differences in primary and repeat lower extremity amputation: results from a multihospital study. J Vasc Surg. 2005;41:823–829
  34. Rucker-Whitaker C, Feinglass J, Pearce WH. Explaining racial variation in lower extremity amputation: a 5-year retrospective claims data and medical record review at an urban teaching hospital. Arch Surg. 2003;138:1347–1351
  35. Dillingham TR, Pezzin LE, Shore AD. Reamputation, mortality, and health care costs among persons with dysvascular lower-limb amputations. Arch Phys Med Rehabil. 2005;86:480–486
  36. Massey D. Segregation and stratification: a biosocial perspective. DuBois Rev. 2004;1:7–25
  37. Baltrus PT, Lynch JW, Everson-Rose S, Raghunathan TE, Kaplan GA. Race/ethnicity, life-course socioeconomic position, and body weight trajectories over 34 years: the Alameda County Study. Am J Public Health. 2005;95:1595–1601
  38. Kimm SY, Barton BA, Obarzanek E, McMahon RP, Sabry ZI, Maclawiw MA, et al. Racial divergence in adiposity during adolescence: The NHLBI Growth and Health Study. Pediatrics. 2001;107:E34
  39. Chin MH ZJ, Merrell K. Diabetes in the African American Medicare population. Diabetes Care. 1998;21:1090–1095
  40. Hasnain-Wynia R, Baker DW, Nerenz D, Feinglass J, Beal AC, Landrum MB, et al. Disparities in health care are driven by where minority patients seek care: examination of the hospital quality alliance measures. Arch Intern Med. 2007;167:1233–1239
  41. Selby JV, Zhang D. Risk factors for lower extremity amputation in persons with diabetes. Diabetes Care. 1995;18:509–516
  42. Barbeau EM, Krieger N, Soobader MJ. Working class matters: socioeconomic disadvantage, race/ethnicity, gender, and smoking in NHIS 2000. Am J Public Health. 2004;94:269–278
  43. Dell JL, Whitman S, Shah AM, Silva A, Ansell D. Smoking in six diverse Chicago communities--a population study. Am J Public Health. 2005;95:1036–1042
  44. Lantz PM, House JS, Lepkowski JM, Williams DR, Mero RP, Chen J. Socioeconomic factors, health behaviors, and mortality: results from a nationally representative prospective study of US adults. JAMA. 1998;279:1703–1708
  45. Sudano JJ, Baker DW. Explaining US racial/ethnic disparities in health declines and mortality in late middle age: the roles of socioeconomic status, health behaviors, and health insurance. Soc Sci Med. 2006;62:909–922
  46. Thomas AJ, Eberly LE, Davey Smith G, Neaton JD, Stamler J. Race/ethnicity, income, major risk factors, and cardiovascular disease mortality. Am J Public Health. 2005;95:1417–1423
  47. Eslami MH, Zayaruzny M, Fitzgerald GA. The adverse effects of race, insurance status, and low income on the rate of amputation in patients presenting with lower extremity ischemia. J Vasc Surg. 2007;45:55–59
  48. Manolio TA, Burke GL, Psaty BM, Newman AB, Haan M, Powe N, et al. Black-white differences in subclinical cardiovascular disease among older adults: the Cardiovascular Health Study (CHS Collaborative Research Group). J Clin Epidemiol. 1995;48:1141–1152
  49. Ebaugh JL, Feinglass J, Pearce WH. The effect of hospital vascular operation capability on outcomes of lower extremity arterial bypass graft procedures. Surgery. 2001;130:561–567discussion 567-9

 Competition of interest: none.

PII: S0741-5214(07)02119-2

doi:10.1016/j.jvs.2007.11.072

Refers to article:

  • Invited commentary

    Thomas G. Lynch, G. Matthew Longo
    Journal of Vascular Surgery May 2008 (Vol. 47, Issue 5, Page 1007)

Journal of Vascular Surgery
Volume 47, Issue 5 , Pages 1001-1007, May 2008

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