Independent Observational Analysis of Ulcer Outcomes for SINBAD and University of Texas Ulcer Scoring Systems

Objective: The aim of this study was to compare the University of Texas (UT) and Site, Ischemia, Neuropathy, Bacterial Infection, and Depth (SINBAD) foot ulcer scores in predicting ulcer outcome, within a routine diabetes foot clinic.

Research Design and Methods: From 2006 to 2018, data were collected from all patients attending an outpatient diabetes foot clinic with an active ulcer not healed within 4 weeks. UT and SINBAD were compared in predicting ulcer outcome. A unified numerical score for UT was constructed and compared with UT grade (depth) and stage scores. Outcomes included death, a healed ulcer, or a nonhealed ulcer, which included major or minor amputation and nonhealing chronic ulcers.

Results: Outcomes were available from 1,645 ulcer outcomes in 1,068 patients (mean [SD] age 65.4 [4] years, 72% male), of which 1,108 (67%) healed. With exclusion of death as an adverse outcome, the c-statistic (area under operator curve) was 0.67 (95% CI 0.65-0.71) for UT grade/depth and 0.64 (0.61-0.67) for UT stage. The new unified UT score had an improved c-statistic of 0.71 (0.68-0.74). The c-statistic was 0.72 (0.69-0.75) for SINBAD. There was a stepwise decrease in the proportion of ulcers healed for each increased score on ulcer grading for both grading schemes.

Conclusions: This large and independent observational comparison, in a real-world clinical setting, demonstrated that the UT and SINBAD diabetes foot ulcer grading schemes had similar prognostic ability for predicting foot ulcer outcomes. We have devised and validated a unified numerical scoring system for UT.