A comparison of two diabetic foot ulcer classification systems: the Wagner and the University of Texas wound classification systems.

Abstract

In this study the following two ulcer classification systems were applied to new foot ulcers to compare them as predictors of outcome: the Wagner (grade) and the University of Texas (LT) (grade and stage) wound classification systems. Ulcer size, appearance, clinical evidence of infection, ischemia, and neuropathy at presentation were recorded, and patients were followed up until healing or for 6 months. Of 194 patients with new foot ulcers, 67.0% were neuropathic, 26.3% were neuroischemic, 1.0% were ischemic, and 5.7% had no identified underlying factors. Median (interquartile range [IQR]) ulcer size at presentation was 1.5 cm2 (0.6-4.0). Lower-limb amputations were performed for 15% of ulcers, whereas 65% healed [median (IQR) healing time 5 (3-10) weeks] and 16% were not healed at study termination; 4% of patients died. Wagner grade (P < 0.0001), and UT grade (P < 0.0001) and stage (P < 0.001) showed positive trends with increased number of amputations. For UT stage, the risk of amputation increased with infection both alone (odds ratio [OR] = 11.1, P < 0.0001) and in combination with ischemia (OR = 14.7, P < 0.0001), but not significantly with ischemia alone (OR = 4.6, P = 0.09). Healing times were not significantly different for each grade of the Wagner (P = 0.1) or the UT system (P = 0.07), but there was a significant stepwise increase in healing time with each stage of the UT system (P < 0.05), and stage predicted healing (P < 0.05). Increasing stage, regardless of grade, is associated with increased risk of amputation and prolonged ulcer healing time. The UT system's inclusion of stage makes it a better predictor of outcome.