The research team estimated rates of major lower-limb amputation per 100,000 Medicare beneficiaries between 2010 and 2018 by ZIP code (among ZIP codes with at least 100 beneficiaries). They identified demographic characteristics of ZIP codes with high- and low-amputation rates, and the association between major amputation rate and three markers of socioeconomic status in the ZIP codes—the proportion of patients with dual eligibility for Medicaid, median household income, and Distressed Communities Index score—for metropolitan, micropolitan, and rural ZIP code cohorts.
The data indicated that between 2010 and 2018, 188,995 Medicare fee‐for‐service patients living in 31,391 ZIP codes had a major lower-limb amputation. The median (interquartile range) ZIP code–level number of amputations per 100,000 beneficiaries was 262 (75-469). Though nonmetropolitan ZIP codes had higher rates of major amputation than metropolitan areas, 78.2 percent of patients undergoing major amputation lived in metropolitan areas.
Compared with ZIP codes with lower amputation rates, top quartile amputation rate ZIP codes had a greater proportion of Black residents (4.4 percent versus 17.5 percent). In metropolitan areas, after adjusting for clinical comorbidities and demographics, every $10,000 lower median household income was associated with a 4.4 percent higher amputation rate. A ten‐point higher Distressed Communities Index score was associated with a 3.8 percent higher amputation rate. The researchers found no association between the proportion of patients eligible for Medicaid and amputation rate. The findings were comparable to the associations identified across all ZIP codes.
Based on the data, the researchers concluded that in metropolitan areas, where most individuals undergoing lower-limb amputations live, markers of lower socioeconomic status and Black race were associated with higher rates of major lower-limb amputation.
“We found that closer proximity to specialized PAD care within metropolitan areas does not ensure access to high-quality care,” the lead study author Alexander Fanaroff, MD, told Everday Health. “Limb amputation can be delayed and or prevented by timely and aggressive treatment. However, lack of access to specialized care may delay PAD diagnosis and limit efforts to save the limbs if it has progressed to the advanced disease stage.”
Fanaroff is an interventional cardiologist and an assistant professor at the Perelman School of Medicine at the University of Pennsylvania.
The study, “Geographic and Socioeconomic Disparities in Major Lower Extremity Amputation Rates in Metropolitan Areas,” was published in the Journal of the American Heart Association.