Geographic disparities in lower extremity amputation rates

A new study reveals the highest rates associated with poor and Black ZIP codes.

A lower extremity amputation in a patient with peripheral artery disease—narrowing of the arteries that supply blood to the legs or feet—is the culmination of years of failure by the U.S. health system. A new study published in the Journal of the American Heart Association shows that all too frequently, these failures affect Black people and those of low socioeconomic status.

Map highlighting Phiadelphia, Miami, Detroit and Atlanta and demographics in those cities
The colocalization of majority Black race and high amputation rate ZIP codes in four selected U.S. cities. (Image: Fanaroff et al., Journal of the American Heart Association, 2021)

Amputation is the last step in a years-long process of the build-up of atherosclerotic plaque in the arteries of the lower extremity. Atherosclerotic plaque begins to develop in the teenage years, and progresses through young adulthood and into middle age. It is spurred on by well-known and treatable risk factors: high cholesterol, high blood pressure, smoking, diabetes, lack of physical activity. Eventually, arteries become so narrowed that patients may develop cramping and pain in their legs with walking. Ultimately, the narrowing can progress to the point that there is not enough blood supply to heal wounds and even a small cut on the foot can lead to infection and the need for amputation. At every stage along this decades-long journey, there are opportunities to intervene and stop or slow the progression to amputation.

Prior studies have shown that people living in rural areas, especially poor and non-white people, have higher rates of amputation. The lay press has also focused on this population. The prevailing hypothesis is that distance from subspecialty cardiovascular and peripheral artery disease care, which is concentrated in urban centers, represents a key barrier for these patients. However, less than 20% of Americans live in rural areas, and geographic distance is only one of a number of barriers to health care that may be faced by poor and non-white individuals.

This story is by Alexander Craig Fanaroff. Read more at Penn LDI.