Screening techniques to identify people at high risk for diabetic foot ulceration - A prospective multicenter trial

OBJECTIVE - Diabetic foot ulceration is a preventable long-term complicatio n of diabetes. A multicenter prospective follow-up study was conducted to d etermine which risk factors in foot screening have a high association with the development of foot ulceration. RESEARCH DESIGN AND METHODS - A total of 248 patients from 3 large diabetic foot centers were enrolled in a prospective study. Neuropathy symptom scor e, neuropathy disability score (NDS), vibration perception threshold (VPT), Semmes-Weinstein monofilaments (SWFs),joint mobility, peak plantar foot pr essures, and vascular status were evaluated in all patients at the beginnin g of the study Patients were followed-up every 6 months for a mean period o f 30 months (range 6-40), and all new foot ulcers were recorded. The sensit ivity, specificity, and positive predictive value of each risk factor were evaluated. RESULTS - Foot ulcers developed in 95 feet (19%) or 73 patients (29%) durin g the study. Patients who developed foot ulcers were more frequently men, h ad diabetes for a longer duration, had nonpalpable pedal pulses, had reduce d joint mobility, had a high NDS, had a high VPT and had an inability to fe el a 5.07 SWE NDS alone had the best sensitivity, whereas the combination o f the NDS and the inability to feel a 5.07 SWF reached a sensitivity of 99% . On the other hand, the best specificity for a single factor was offered b y foot pressures, and the best combination was that of NDS and foot pressur es. Univariate logistical regression analysis yielded a statistically signi ficant odds ratio (OR) for sex, race, duration of diabetes, palpable pulses , history of foot ulceration, high NDSs, high VPTs, high SWFs, and high foo t pressures. In addition, 94 (99%) of the 95 ulcerated feet had a high NDS and/or SWF; which resulted in the highest OR of 26.2 (95% CI 3.6-190). Furt hermore, in multivariate logistical regression analysis, the only significa nt factors were high NDSs, VPTs, SWFs, and foot pressures. CONCLUSIONS - Clinical examination and a 5.07 SWF test are the two most sen sitive tests in identifying patients at risk for foot ulceration, especiall y when the tests are used in conjunction with each other. VPT measurements are also helpful and can be used as an alternative. Finally, foot pressure measurements offer a substantially higher specificity and can be used as a postscreening test in conjunction with providing appropriate footwear.