Risk factors associated with diabetic foot ulcer-free survival in patients with diabetes

Abstract

Aims: This study was done to assess the risk factors associated with diabetic foot ulcer-free survival in patients with diabetes.

Materials and methods: Based on a prospective cohort study, ADFC (Ahvaz Diabetic Foot Cohort) study, carried out in a university hospital, all of the patients with diabetes were followed up for new diabetic foot ulcer (DFU). The time of ulcer development was final outcome during two years in the present study. To analyze the data, the variables were first evaluated by univariate analysis. Subsequently variables with P value <0.2 were tested in multivariate analysis, using backward elimination multiple Cox regression.

Results: From among 605 eligible patients of ADFC study, 566 patients without foot ulcer were included for a 2- years follow-up. Thirty subjects (5.3%) developed DFU during the study course none of whom underwent amputation. The DFU-free survival rate was 0.945 over two years of follow-up. In final multivariate Cox regression analysis, the variables which remained in the model and had a statistically significant relationship with time to develop foot ulcer were: dyslipidemia, history of DFU or amputation, nephropathy callus formation in the feet and diabetes duration. Foot deformity and patients' training about self-care of their feet were statistically borderline significant.

Conclusions: The DFU-free survival rate was 0.945 over two years of follow-up. In this study, independent risk factors associated with ulcer-free survival in diabetic foot patients were dyslipidemia, prior history of DFU or amputation, diabetic nephropathy, callus formation in the feet and diabetes duration.

Keywords: DFU-free survival; Diabetic foot ulcer; Risk factor; Survival.