2019 HSR&D/QUERI National Conference

4112 — Risk of ipsilateral re-amputation following an incident toe amputation among Veterans with diabetes, 2005-2017

Lead/Presenter: Alyson Litttman,  COIN - Seattle/Denver
All Authors: Littman AJ (Seattle-Denver Center of Excellence for Veteran-Centered and Value-Driven Care and Seattle ERIC and University of Washington), Tseng CL (VA New Jersey Healthcare System), Timmons A (Seattle ERIC) Landry GJ (Oregon Health & Science University) Czerniecki JM (VA Puget Sound, University of Washington, VA RR&D Center for Limb Loss and Mobility) Robbins JM (Louis Stokes Cleveland VA Medical Center) Tseng CL (VA NJ Health Care System) Boyko EJ (Seattle ERIC, VA Puget Sound, University of Washington)

Nearly a quarter of US Veterans have diabetes, which causes micro- and macro-vascular damage, putting individuals at risk of limb-threatening foot infections. The goal of this study was to determine the extent to which the incidence of 1-year subsequent ipsilateral amputation and death following an incident toe amputation has changed over time and by demographic characteristics and region.

We conducted a cohort study using national data from VHA. Eligibility criteria included having diabetes and an incident (first) toe amputation between 2005 and 2016 in VHA. Laterality of incident and subsequent amputations were determined based on Current Procedural Terminology modifier codes and natural language processing. Because the sample size was large, we focus our presentation on differences of clinical importance, defined as at least 5 percentage points.

Of 17,849 individuals (98.5% male, mean age = 64.8 years) who met inclusion criteria, 34% (n = 6040) had a subsequent ipsilateral amputation within 1 year of incident toe amputation and 12% died. Incidence of ipsilateral re-amputation decreased over time, though this was largely due to a decrease in subsequent major amputations; rates of subsequent minor amputations did not change significantly. Incidence of ipsilateral re-amputation was more frequent among men (34%) than women (29%) and among American Indian/Alaska Natives (39%), and African Americans (39%) compared to Whites (34%). Ipsilateral re-amputation rate generally increased with increasing comorbidity burden (from 27% in the lowest category of the Gagne index to 39% in the highest category). Re-amputation was greater among those in urban areas (35%) than highly rural areas (26%) and intermediate among those in rural areas (32%). There was substantial variation across states/territories; Maine had the lowest re-amputation rate (19%) and Puerto Rico (46%) had the highest.

More than one in three individuals undergo an ipsilateral amputation in the year following a toe amputation, and nearly a third of those amputations are major. The racial and geographic differences observed merit further study to understand likely causes.

Data from this study identify important correlates of variation in re-amputation and will be critical to determining ways to reduce major amputation rates in the future.