Diabetic neuropathic foot ulcers: predicting which ones will not heal

Neuropathic foot ulcers are a serious complication of diabetes. The purpose of this study was to develop a clinically useful prognostic model for identifying ulcers that are not likely to heal.

Using an administrative and medical records database from a large wound care system, we designed a cohort study of patients with diabetic neuropathic foot ulcer. Clinicians followed a standard algorithm of good wound care, wound débridement, and wound offloading. The outcome was a healed wound by week 20 of care. For patients with more than one wound, we investigate the wound labeled as the primary wound. We evaluated several prognostic models of varying mathematical complexity.

We studied 27630 patients with a diabetic neuropathic foot ulcer, of whom 12983 (47%) healed by week 20 of care. The simplest model counted 1 point each if the wound was older than 2 months, larger than 2 cm(2), or had a grade > or =3 (on a 6-point scale). The likelihood that a wound would not heal was 0.35 for a count of 0, 0.47 for a count of 1, 0.66 for a count of 2, and 0.81 for a count of 3 in the validation data set.

A simple prognostic model can be developed using prognostic factors that are already part of the wound care examination. Applications of this model could include determining who will do well with standard care and as an aid in the design of clinical trials.