Examining Racial Disparities in Lower Extremity Amputation Outcomes Among Patients with Diabetic Foot Ulcers in North America: A Multicohort Study
Mehul M. Mittal, Sri Tummala, Katherine M. Raspovic, Matthew J. Johnson, Senthil N. Sambandam, Andrew J. M. Boulton, David G. Armstrong, Dane K. WukichObjective:
Racial and ethnic disparities in diabetic foot ulcer (DFU) outcomes are well described. We examined whether differences in major and minor lower extremity amputation (LEA) persist after matching for comorbidities, and whether the level of amputation identifies opportunities for earlier limb-preservation intervention.
Approach:
In this retrospective, propensity-matched cohort study using the TriNetX network (2002–2019), reported in accordance with Strengthening the Reporting of Observational Studies in Epidemiology, adults with DFU were identified by diagnostic codes and stratified by race/ethnicity. Minor and major LEA risks were compared with a matched White (non-Hispanic) reference, reporting both relative and absolute risks. We also calculated the high-to-low (Hi-Lo) ratio (major:minor).
Results:
Among 388,371 adults with DFU and after matching, Hispanic and African American patients had higher minor, major, and overall LEA risk than White patients (major-LEA absolute risk 3.0–4.7% vs. ∼2.7%; relative risks up to 1.89). Asian patients had the lowest risk. Native American patients had the highest Hi-Lo (major-to-minor amputation) ratio despite no significant increase in major-LEA risk, suggesting potential differences in disease presentation or access to limb-preservation care that warrant further study. Disparities persisted after adjustment for diabetes-related comorbidities and peripheral arterial disease.
Innovation:
Applied to a multiethnic DFU cohort, the Hi-Lo ratio gave a descriptive view of major- versus minor-amputation burden, most notably in Native American patients.
Conclusion:
The Hi-Lo amputation ratio may identify populations experiencing disproportionate major limb loss and help prioritize earlier vascular assessment, multidisciplinary limb-preservation referral, and posthealing surveillance. Persistent racial and ethnic differences after matching warrant further study of disease severity, access, and care delivery.
Dane K. Wukich, MD, MSc