Infrared thermography and ulcer prevention in the high-risk diabetic foot: data from a single-blind multicentre controlled clinical trial.

Abstract

To assess the usefulness of monthly thermography and standard foot care to reduce diabetic foot ulcer recurrence. People with diabetes (n=110), neuropathy and history of≥1 foot ulcer participated in a single-blind multicentre clinical trial. Feet were imaged with a novel thermal imaging device (Diabetic Foot Ulcer Prevention System). Participants were randomized to intervention (active thermography + standard foot care) or control (blinded thermography + standard foot care) and were followed up monthly until ulcer recurrence or for 12months. Foot thermograms of participants from the intervention group were assessed for hot spots (areas with temperature≥2.2°C higher than the corresponding contralateral site) and acted upon as per local standards. After 12months, 62% of participants were ulcer-free in the intervention group and 56% in the control group. The odds ratios of ulcer recurrence (intervention vs control) were 0.82 (95% CI 0.38, 1.8; P=0.62) and 0.55 (95% CI 0.21, 1.4; P=0.22) in univariate and multivariate logistic regression analyses, respectively. The hazard ratios for the time to ulcer recurrence (intervention vs control) were 0.84 (95% CI 0.45, 1.6; P=0.58) and 0.67 (95% CI 0.34, 1.3; P=0.24) in univariate and multivariate Cox regression analyses, respectively. Monthly intervention with thermal imaging did not result in a significant reduction in ulcer recurrence rate or increased ulcer-free survival in this cohort at high risk of foot ulcers. This trial has, however, informed the design of a refined study with longer follow-up and group stratification, further aiming to assess the efficacy of thermography to reduce ulcer recurrence.