Nontraumatic lower-extremity amputations (LEA) are a devastating consequence of diabetes. Persons age 65 and older account about 50% of persons with diabetes who had nontraumatic lower-extremity amputations. African Americans (AA) age 65 or older with diabetes are at increased risk of such amputations. Internationally, substantial geographic variation exists in incidence of LEAs between and within nations. In the United States, comparisons between hospital referral regions have shown nine-fold variation. Studies that have assessed the extent of the variation of LEA among smaller geographic areas, such as counties, are not available. The purpose of the revised exploratory study is to: 1) characterize the geographic variation of the incidence of diabetes-related LEA at the county level among AA and white persons age 65-99 in 3 southern states, and 2) explore the association of selected determinants with the geographic variation in diabetes-related incidence of LEA among AA and white persons age 65-99 in 3 southern states. These determinants have been selected based on 1) those previously suggested as explanation of the geographic variation that was observed in LEA rates; 2) emerging research that shows that persons in areas with adverse socioeconomic conditions have lower health status, more disease, more surgical procedures, and a higher rate of avoidable hospitalizations among persons with diabetes; and 3) risk factors for LEA regardless of their geographic variation. The study area has been selected based on the 25 percent or more AA persons in these 3 southern states. Based on the reviewers' comments, we have provided greater detail about the data quality, the likelihood of useful outcomes, and aspects about the proposed statistical analysis. Using an ecological study design, existing data sources will be linked and analyzed, including Medicare claims data (LEA, foot ulcers, peripheral vascular disease, diabetes), Provider of Services file (availability of medical providers), and the 2000 census data (area sociodemographics). We will use county-rates of LEA among AA and white persons age 65-99 with diabetes as the outcome measure. This exploratory study will serve to focus subsequent, more in-depth studies on identifying additional underlying factors that could determine why those with diabetes are at increased risk of LEA in specific geographic areas in a future RO1.

R21DK067172

2004-09-30

2007-08-31