Risk factors identified for lower-limb amputation for peripheral artery disease in urban areas

Lower socioeconomic status and Black race are associated with higher rates of major lower-extremity amputation in patients with peripheral artery disease, even in metropolitan areas, according to a study published online Aug. 25 in the Journal of the American Heart Association.

Alexander C. Fanaroff, M.D., from the University of Pennsylvania in Philadelphia, and colleagues estimated the rates of major lower-extremity amputation per 100,000 Medicare beneficiaries between 2010 and 2018 at the ZIP code level. Data were included for 188,995 Medicare fee-for-service patients living in 31,391 ZIP codes who had a major lower-extremity amputation.

The researchers found that the median ZIP code-level number of amputations was 262 per 100,000 beneficiaries. Compared with metropolitan areas, nonmetropolitan ZIP codes had higher rates of major amputation; however, 78.2 percent of the patients undergoing amputation lived in metropolitan areas. The proportion of Black residents was higher in the top quartile amputation rate ZIP codes compared with ZIP codes with lower amputation rates (17.5 versus 4.4 percent). After adjustment for clinical comorbidities and demographics, in metropolitan areas, the amputation rate was 4.4 percent higher for every $10,000 lower median household income and 3.8 percent higher for each 10-point higher Distressed Communities Index score. No association was seen between the proportion of patients eligible for Medicaid and amputation rate.

“Though amputation rates are generally higher in rural areas, this finding shows that the association between lower socioeconomic status, race, and amputation rate extends to major metropolitan areas as well as rural regions,” Fanaroff said in a statement.

Two authors disclosed financial ties to the biotechnology and medical device industries.