METHODOLOGICAL ISSUES AFFECT VARIABILITY IN REPORTED INCIDENCE OF LOWER-EXTREMITY AMPUTATIONS DUE TO DIABETES

The aim of this study is to evaluate the influence of different method ological techniques commonly utilized to identify the incidence of dia betes related lower extremity amputations. Medical records for each ho spitalization for an amputation in 1993 in six metropolitan statistica l areas in South Texas were abstracted. Every hospitalization, amputat ion and amputee was identified to allow separate analysis. Furthermore , data was categorized by ethnicity, level and age. Diabetes was verif ied using WHO criteria. Incidence rates were calculated per 10 000 dia betic patients at risk per year, both diagnosed only (DO) and diagnose d and undiagnosed combined (DUC). In total 1922 amputations were carri ed out during 1228 hospitalizations for 1043 amputees. The incidence r ates per 10 000 diabetic patients (DO) were: 157.6 amputations, 101.2 hospitalizations and 87.0 amputees. When calculated using the DUC popu lation at risk the rates were: 92.8 amputations, 59.6 hospitalizations and 51.2 amputees. Trends were found to be similar when analyzed by g ender and ethnicity. The variability detected using of different metho dological techniques to determine incidence rates is considerable and may have significant consequences when rates from different studies ar e compared. (C) 1997 Elsevier Science Ireland Ltd.