Diabetic foot infection (DFI) is an important risk factor for amputation, and late diagnosis or referral is often incriminated for poor outcome. To enable an earlier diagnosis of DFI, comparative foot thermometry has been suggested as a self-screening method for patients in a home setting. We validated the efficacy of the ThermoScale, a weighing scale outfitted with temperature sensors that allows accurate temperature measurement in both feet. Temperature differentials in DFI patients (n = 52) were compared with a control group of similar diabetic patients (n = 45) without any foot wounds. Based on these findings, we drafted a receiver operating characteristic curve to determine an area-under-the-curve of 0.8455. This value suggests that the ThermoScale, as a diagnostic test, is reasonably accurate. A cutoff value of 2.15 °C temperature difference corresponded with a sensitivity of 88.9% and a specificity of 61.5%. As wearables, portable health electronics, and telemedicine become increasingly popular, we think that comparative temperature measurement technology is valuable in improving early diagnosis of DFIs.
Keywords: diabetic foot; diagnostics; infection; screening; thermometry.