Reduced incidence of lower-limb amputations in the diabetic population of a German city, 1990-2005

OBJECTIVE - We evaluated whether the incidence of amputations in one German city (Leverkusen, population similar to 160,000) had decreased between 1990 and 2005. RESEARCH DESIGN AND METHODS - From all three hospitals in the city, we obtained complete lists of nontraumatic lower-limb amputations in 1990-1991 and 19942005: Only the first observed amputation in residents of Leverkusen was counted. A total of 692 patients met the inclusion criteria. Data about the population stucture, separately for each year of the observation period, were received from the city administration and the Federal Office of Statistics. To test for time trend, we fitted Poisson regression models. RESULTS- Of all subjects, 72% had known diabetes and 58% were male. Mean age was 71.7 years. Incidence rates in the diabetic population (standardized to the estimated German diabetic population per 100,000 person-years) varied considerably between years (maximum 549 in 1990, minimum 281 in 2004). In the diabetic population, the estimated relative risk (RR) per year was 0.976 (95% CI 0.958-0.996, P = 0.0164). The same trend was observed when only amputations above the ankle (n = 352) (RR 0.970 [95% CI 0.943-0.997], P = 0.0318) were considered. Over 15 years, an estimated reduction of amputations above the toe level by 37.1% (95% CI 12.3-54.8) results. There was no significant change of incident amputations in the nondiabetic population (RR 1022 [0.989 -1.056], P = 0.1981). CONCLUSIONS - This finding is likely to be due to improved management of the diabetic foot syndrome after a network of specialized physicians and defined clinical pathways for wound treatment and metabolic control were introduced.