The burden of amputation among hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Background: Hemodialysis patients are at increased risk of amputation, particularly those with diabetes. Limited data exist about the prevalence, incidence, risk factors for, and sequelae of amputation in hemodialysis patients. Study Design: A prospective observational study of hemodialysis practices and outcomes. Setting & Participants: Data from 29,838 patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) from 1996 to 2004 were analyzed. Predictor/Factor: Demographic factors, comorbid conditions, laboratory values, years since end-stage renal disease onset, and currently prescribed medications at study enrollment. Outcome: Prior amputation at study enrollment by using logistic regression and amputation during follow-up by using Cox models. Amputation was ascertained from medical record review. Results: There was a high prevalence (6%) and incidence (2.0 events/100 patient-years at risk) of amputation in hemodialysis patients; patients with diabetes had a more than 9 times greater incidence of new amputation. Wide variations among countries were observed in risk of amputation, with the lowest prevalence in Japan and the highest in Belgium, France, and Germany. Traditional cardiovascular risk factors, such as age, peripheral vascular disease, and smoking were predictive of amputation, as were such risk factors related to hemodialysis as altered mineral metabolism and years of hemodialysis therapy. In patients with diabetes, greater relative risks of amputation were observed in men, smokers, and those with other diabetic complications, anemia, and malnutrition. The relative risk of mortality after amputation was 1.54 (95% confidence interval, 1.41 to 1.68; P < 0.001) with a mean survival of 2.0 versus 3.8 years. Limitations: The database does not differentiate between types of amputations; some amputations may have concerned the upper limbs and could have been linked to ischemia related to vascular access. Conclusions: Amputation in hemodialysis patients is a very frequent event, particularly in patients with diabetes, and is associated with both traditional cardiovascular risk factors and factors linked to kidney failure treated by hemodialysis. Interventional trials are needed to reduce the burden of amputation. Am J Kidney Dis 54:680-692. (C) 2009 by the National Kidney Foundation, Inc