Association of Race and Rurality With Diabetic Foot Ulcer Outcomes

Quick Takes

  • There is a significantly higher rate of major leg amputation or death among Blacks with diabetic foot ulcers.
  • Furthermore, rural patients identifying as Black had an observed 28.1% risk of undergoing a major leg amputation or death after admission for a diabetic foot ulcer.
  • These data suggest that there is interaction between racial and rural disparities amplifying risk of increase in the rate of major amputation or death.

Study Questions:

What are the associations between intersecting identities of Black race, ethnicity, rural residence, or living in a disadvantaged neighborhood with risk of major leg amputation or death among Medicare beneficiaries hospitalized with diabetic foot ulcers?

Methods:

The investigators conducted a retrospective cohort study using 2013-2014 data from the US National Medicare Claims Data Database on all adult Medicare patients hospitalized with a diabetic foot ulcer. Statistical analysis was conducted from August 1–October 27, 2021. Race was categorized using Research Triangle Institute variables. Rurality was assigned using Rural-Urban Commuting Area codes. Residents of disadvantaged neighborhoods comprised those living in neighborhoods at or above the national 80th percentile Area Deprivation Index. The main outcome measures were major leg amputation or death during hospitalization or within 30 days of hospital discharge. Logistic regression was used to explore interactions among race, ethnicity, rurality, and neighborhood disadvantage, controlling for sociodemographic characteristics, comorbidities, and ulcer severity.

Results:

The cohort included 124,487 patients, with a mean (SD) age of 71.5 (13.0) years, of whom 71,286 (57.3%) were men, 13,100 (10.5%) were rural, and 21,649 (17.4%) identified as Black. Overall, 17.6% of the cohort (n = 21,919), 18.3% of rural patients (2,402 of 13,100), and 21.9% of patients identifying as Black (4,732 of 21,649) underwent major leg amputation or died. Among 1,239 rural patients identifying as Black, this proportion was 28.0% (n = 347). This proportion exceeded the expected excess for rural patients (18.3% − 17.6% = 0.7%) plus those identifying as Black (21.9% − 17.6% = 4.3%) by more than two-fold (28.0% − 17.6% = 10.4% vs. 0.7% + 4.3% = 5.0%). The adjusted predicted probability of major leg amputation or death remained high at 24.7% (95% confidence interval, 22.4%-26.9%), with a significant interaction between race and rurality.

Conclusions:

The authors concluded that rural patients identifying as Black had a >10% absolute increased risk of major leg amputation or death compared with the overall cohort.

Perspective:

This study reports significantly higher rates of major leg amputation or death among all patients identifying as Black compared with the overall cohort. Furthermore, rural patients identifying as Black had an observed 28.1% risk of undergoing a major leg amputation or death after admission for a diabetic foot ulcer. These data suggest that there is interaction between racial and rural disparities amplifying risk of increase in the rate of major amputation or death. Overall, these findings support using both race and rurality to address disparities among patients with diabetic foot ulcers and improve outcomes.

Clinical Topics: Geriatric Cardiology, Prevention, Vascular Medicine

Keywords: African Americans, Amputation, Cardiometabolic Risk Factors, Diabetes Mellitus, Diabetic Foot, Ethnic Groups, Geriatrics, Outcome Assessment, Health Care, Patient Discharge, Primary Prevention, Residence Characteristics, Vascular Diseases


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