Background: We sought to study the impact of foot complications on 10-year mortality independent of other demographic and biological risk factors in a racially and socioeconomically diverse managed-care population with access to high-quality medical care.
Methods: We studied 6,992 patients with diabetes in Translating Research Into Action for Diabetes (TRIAD), a prospective observational study of diabetes care in managed care. Foot complications were assessed using administrative claims data. The National Death Index was searched for deaths across 10 years of follow-up (2000-2009).
Results: Charcot's neuro-osteoarthropathy and diabetic foot ulcer with debridement were associated with an increased risk of mortality; however, the associations were not significant in fully adjusted models. Lower-extremity amputation (LEA) was associated with an increased risk of mortality in unadjusted (hazard ratio [HR], 3.21; 95% confidence interval [CI], 2.50-4.12) and fully adjusted (HR, 1.84; 95% CI, 1.28-2.63) models. When we examined the associations between LEA and mortality stratified by sex and race, risk was increased in men (HR, 1.96; 95% CI, 1.25-3.07), Hispanic individuals (HR, 5.17; 95% CI, 1.48-18.01), and white individuals (HR, 2.18; 95% CI, 1.37-3.47). In sensitivity analyses, minor LEA tended to increase the risk of mortality (HR, 1.48; 95% CI, 0.92-2.40), and major LEA was associated with a significantly higher risk of death at 10 years (HR, 1.89; 95% CI, 1.18-3.01).
Conclusions: In this managed-care population with access to high-quality medical care, LEA remained a robust independent predictor of mortality. The association was strongest in men and differed by race.