Wool-derived keratin dressings versus usual care dressings for treatment of slow healing venous leg ulceration: a randomised controlled trial (Keratin4VLU)

OBJECTIVE: To determine the effect of a keratin dressing for treating slow-to-heal venous leg ulcers (VLU) on VLU healing. DESIGN: Pragmatic parallel group randomised controlled trial. SETTING: Community-dwelling participants. PARTICIPANTS: People aged 18 or more years with VLU (either present for more than 26 weeks or ulcer area larger than 5 cm(2) or both). INTERVENTION: Wool-derived keratin dressing or usual care formulary of non-medicated dressings, on a background treatment with compression. PRIMARY AND SECONDARY OUTCOME MEASURES: Healing at 24 weeks based on blinded assessment of ulcer photographs. Other outcomes included time to complete healing, change in ulcer area to 24 weeks, change in health-related quality of life and incidence of adverse events. RESULTS: We screened 1068 patients with VLU and randomised 143 participants (51.1% of target recruitment), 71 to the keratin dressing group and 72 to the usual care group. The mean age was 66.1 years (SD 15.9) and 53 participants (37.1%) were women. There were no significant differences between the groups on the primary outcome (risk difference −6.4%, 95% CI −22.5% to 9.7%), change in ulcer area (−1.9 cm(2), 95% CI −16.5 to 12.8 cm(2)), time to complete healing (HR 0.80, 95% CI 0.52 to 1.23) or the incidence of adverse events (incidence rate ratio 1.19, 95% CI 0.89 to 1.59) in the intention-to-treat analyses. However, the direction of effect on the primary outcome was reversed in a per protocol analysis specified a priori (risk difference 6.2%, 95% CI −12.4% to 24.9%). CONCLUSION: The effect of adding a keratin dressing to the treatment regimen for prognostically slow-to-heal VLU remains unclear. TRIAL REGISTRATION NUMBER: NCT02896725