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.