A Prospective Study of the PUSH Tool in Diabetic Foot Ulcers

PURPOSE: The purpose of this study was to examine the predictive validity of Pressure Ulcer Scale for Healing (PUSH; v. 3.0) in monitoring healing of neuropathic foot ulcers in patients with diabetes mellitus. DESIGN: This is a 13-week descriptive, prospective study describing the trajectory of change over time and the time-to-heal associated with PUSH scores. The study monitored a convenience sample of 18 subjects with Wagner 2 or greater neuropathic, nonischemic ulcers on the plantar surface of the foot, which healed completely over a 13-week follow-up period. Every 2 weeks, the study ulcers were evaluated via PUSH. Healing was defined as complete reepithelialization. RESULTS: PUSH scores were modeled using a piecewise linear regression. PUSH values decreased significantly (P <.0001) at a rate of 0.6656 per week, until 2 weeks before healing, and then decreased significantly (P <.0001) at a rate of 2.2496 per week for the last 2 weeks of healing. Conversely, the time-to-heal (in weeks) increased significantly (P <.0001), at a rate of 0.6412 per each unit increase in PUSH for PUSH values of 4 or less, and then significantly (P <.0001) increased at a rate of 1.072 for PUSH values greater than 5. In predicting time-to-heal, the subitem of length X width alone (R-2 = 0.81) is comparable to the total PUSH score (R-2 = 0.76). Individually, exudate (R-2 = 0.36) and tissue type (R-2 = 0.42) are not nearly as useful as length X width. CONCLUSION: Our findings indicate that PUSH scores significantly decrease over time in healing neuropathic diabetic foot ulcers (DFUs) that have no arterial etiologic component. Findings also suggest that total PUSH scores predict time-to-heal for DFU. We showed that a DFU with a PUSH score of 10 would be expected to heal in 8.8 weeks (95% Cl: 7.4-10.2) and a DFU with a PUSH score of 4 in 2.6 weeks (95% Cl: 1.88-3.25). Finally, measurements of size alone predict healing time for neuropathic DFU. This finding could greatly simplify clinical assessments.