The Pima Indians experience one of the highest rates of Type II diabetes in the world and a several-fold higher risk of lower extremity amputation compared to white diabetic patients. The age-sex adjusted amputation rate is 24.1/1000 person years in diabetic Pima Indians. Prior research has documented an increased risk of amputation with male sex, duration of diabetes, and various physiologic variables. This study will extend that research and explore the role of lifestyle variables (e.g., alcoholism, living alone), decreased functional status (e.g., poor visual acuity) and foot care education on the risk of amputation. Health care utilization, access to care, and provider preventive practices (including home health workers) will also be examined for their impact on the risk of amputation. A retrospective case-control study will be performed using existing medical records. All firsttime amputations which occurred to diabetic Pima Indians on the Gila River Reservation between 1985-1992 will be compared to diabetic controls who have not suffered an amputation. The controls will be randomly selected from the same Pima Indian population as the cases. For each case, the pivotal event which led to the amputation will be identified and will mark the end of that case's data collection period. The time periods associated with the cases will be randomly allocated to the controls. The charts for cases and controls will be abstracted for the variables of interest during the assigned time window. Additional data will be obtained from an NIH research database. Logistic regression analyses will be performed to estimate odds ratios for amputation associated with study risk factors. A methodologic study on the feasibility of developing a diabetes registry from automated clinic data will also be performed. The results of this investigation will guide providers in identifying patients with lifestyles that increase their risk of amputation. It should also yield information on the effectiveness of preventive efforts intended to reduce diabetic amputation rates to the Year 2000 goal of 4.9/1000 diabetic individuals.
