Development and validation of a brief diabetic foot ulceration risk checklist among diabetic patients: a multicenter longitudinal study in China

The study aims to develop and assess and validate a brief diabetic foot ulceration risk checklist among diabetic patients through a longitudinal study. Patients who had diabetes mellitus and had no foot ulceration and severe systematic disorders were recruited from eleven tertiary hospitals in nine provinces or municipalities of China. Internal consistency reliability, construct validity, concurrent validity, item property, and measurement invariance of the tool were assessed. The predictive capability of the tool was validated by the follow-up data using the receiver operating characteristic curve. At baseline, 477 valid cases were collected. Twelve items were remained after initial selection. Cronbach’s alpha was 0.56. Confirmatory factor analysis showed that the model had acceptable goodness-of-fit yet local dependency between two items. Item response theory showed that most items had acceptable discrimination and difficulty parameters. Differential item functioning showed that tool had measurement invariance. 278 were followed up one year after the baseline. Follow-up showed that one-year incidence of ulceration among the patients was 3.6%, and the area under the receiver operating characteristic curve was 0.77 (95% confidence interval: 0.61–0.93). The cut-off point of the tool was 4, when sensitivity and specificity were 0.62 and 0.75 respectively. The checklist has good psychometric properties according to mixed evidences from classical and modern test theory, and has good predictive capability.