Factors Associated With Key Outcomes in Diabetes Related Foot Disease: A Prospective Observational Study

Abstract

Diabetic foot disease is a serious and common complication of diabetes mellitus. The aim of this study was to assess limb and patient factors associated with key clinical outcomes in diabetic patients with foot ulcers. This was a prospective observational study of diabetic patients with foot wounds admitted to a major tertiary teaching hospital in South Australia or seen at associated multidisciplinary foot clinics between February 2017 and December 2018. Patient demographic and clinical data were collected, including limb status severity assessed by the WIfI system and grip strength. Participants were followed up for 12 months. The primary outcomes were major amputation, death, amputation free survival, and completion of healing of the index wound within one year. A total of 153 participants were recruited and outcome data were obtained for 152. Forty-two participants underwent revascularisation during the research period. Eighteen participants (11.8%) suffered major amputation of the index limb and 16 (10.5%) died during follow up. Complete wound healing was achieved in 106 (70%) participants. There was a statistically significant association between WIfI stage and major amputation (subdistribution hazard ratio [SHR] 2.75), mortality (hazard ratio [HR] 2.60), amputation free survival (odds ratio [OR] 0.32), and wound healing (SHR 0.69). There was also a statistically significant association between time to healing and grip strength (SHR 0.50), and previous amputations (major or minor) (SHR 0.57). This prospective study supports the ability of the WIfI classification system to predict one year key clinical outcomes in a diabetic population with foot ulcers. It also demonstrated that grip strength may be a useful predictor of wound healing.