The effects of ulcer size and site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers

Aims: The outcome of foot ulcers is affected by wound depth, infection, ischaemia and glycaemic control. The aim of this study was to determine the effects of ulcer size, site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers. Methods: Diabetic patients with new foot ulcers presenting during a 12-month period had demographics and ulcer characteristics recorded at presentation. Ulcers were followed-up until an outcome was noted. Results: One hundred and ninety-four patients (77% males) with a mean (± SD) age and duration of diabetes of 56.6 ± 12.6 and 15.4 ± 9.9 years, respectively, were included in the study. The majority of ulcers were neuropathic (67.0%) and present on the forefoot (77.8%) with a median (interquartile range) area of 1.5 (0.6-4.0) cm². Amputations were performed for 15% of ulcers; 65% healed; 16% remained unhealed and 4% of patients died. The median (95% confidence interval) time to healing was 10 (8.8-11.6) weeks. Ulcer area at presentation was greater in the amputation group compared to healed ulcers (3.9 vs. 1.2 cm², P < 0.0001). Ulcer area correlated with healing time (r_s = 0.27, P < 0.0001) and predicted healing (P = 0.04). Patient's age, sex, duration/type of diabetes, and ulcer site had no effect on outcome. Conclusions: Ulcer area, a measure of ulcer size, predicts the outcome of foot ulcers. Its inclusion into a diabetic wound classification system will make that system a better predictor of outcome.