Rates of lower-extremity amputation among ESRD patients on dialysis have decreased by about half in recent years, but mortality remains high among those who do undergo amputation, reports a study in JAMA Internal Medicine.
The study included 3.7 million records of ESRD patients receiving dialysis from 2000 through 2014, drawn from the US Renal Data System. Yearly cohorts were analyzed to assess trends in nontraumatic lower extremity amputations, classified as major (above- or below-knee) and minor (below-ankle). The effects of age, sex, diabetes, and hospital referral region were examined, along with one-year mortality after amputation.
In each annual cohort, more than half of patients were white; the percentage of women declined over the years. The adjusted rate of lower-extremity amputations declined from 5.42 per 100 person-years in 2000 to 2.66 per 100 person-years in 2014, for a relative decrease of 51%. The trend was driven by a 65.0% decrease in above-knee amputations and a 58.5% decrease in below-knee amputations, but there was also a 25.9% decrease in below-ankle amputations.
Amputation rates were more than five times higher in ESRD patients with diabetes, compared to nondiabetic patients. Adjusted amputation rates were higher for patients under age 65, compared to younger patients, and higher for men versus women. Adjusted 1-year mortality decreased from 52.2% in 2000 to 43.6% in 2013. Amputation rates decreased in all hospital referral regions, but remained higher in the South and Northeast regions. These regional variations persisted after adjustment for demographic variables and comorbidity.
Patients with ESRD receiving dialysis are at high risk of amputation, likely reflecting both traditional risk factors and risks specific to kidney disease. Recent studies have reported declining lower extremity amputation rates in the general Medicare population—possibly due to improved screening and management of peripheral arterial disease, especially in diabetic patients.
This retrospective study finds a 51% relative decrease in lower extremity amputations in dialysis patients since the year 2000. Reasons for this trend may include more aggressive management of cardiovascular risk factors and improved diabetic foot care.
One-year mortality after amputation in dialysis has improved as well, but remains over 40%. “Our results highlight the need for more research on ways to prevent lower extremity amputation in this extremely high-risk population,” the investigators conclude [Franz D, et al. Trends in rates of lower extremity amputation among patients with end-stage renal disease who receive dialysis. JAMA Intern Med 2018; 178:1025–1032].