Survival and factors predicting mortality after major and minor lower-extremity amputations among patients with diabetes: a population-based study using health information systems

IntroductionThe aim of the study was to identify the sociodemographic and clinical factors associated with death after the first lower-extremity amputation (LEA), minor and major separately, using data from regional health administrative databases.Research design and methodsWe carried out a population-based cohort study including patients with diabetes residing in the Lazio region and undergoing a primary amputation in the period 2012–2015. Each individual was followed up for at least 2 years. Kaplan-Meier analysis was used to evaluate long-term survival; Cox proportional regression models were applied to identify factors associated with all-cause mortality.ResultsThe cohort included 1053 patients, 72% were male, 63% aged ≥65 years, and 519 (49%) died by the end of follow-up. Mortality rates at 1 and 4 years were, respectively, 33% and 65% for major LEA and 18% and 45% for minor LEA. Significant risk factors for mortality were age ≥65, diabetes-related cardiovascular complications, and chronic renal disease for patients with minor LEA, and age ≥75 years, chronic renal disease and antidepressant drug consumption for subjects with major LEA.ConclusionsThe present study confirms the high mortality rates described in patients with diabetes after non-traumatic LEA. It shows differences between minor and major LEA in terms of mortality rates and related risk factors. The study highlights the role of depression as specific risk factor for death in patients with diabetes after major LEA and suggests including its definition and management in strategies to reduce the high mortality rate observed in this group of patients.