Supplementary Material for: Effectiveness of Advanced versus Conventional Wound Dressings on Healing of Chronic Wounds: Systematic Review and Meta-Analysis

Background: Wound dressings are essential in the treatment of chronic wounds and should be selected on valid and recent evidence. Objective: Effectiveness of advanced compared to conventional dressings for chronic wound healing. Methods: Comprehensive literature search, systematic review and meta-analyses of the results of advanced dressing studies on chronic wound treatment. Comprehensiveness and coverage of all relevant studies is the most striking difference in relation to other meta-analyses and systematic reviews. Results: The mean odds ratio of complete healing was 1.52 favouring advanced over conventional dressings in 65 controlled trials. In 287 study conditions including uncontrolled studies, mean odds were 0.97 (advanced dressings/controlled studies), 0.77 (conventional/controlled) and 0.47 (advanced/uncontrolled). The overall healing rate was 33%. When causal treatment was applied, a reduced effect was observed. The consideration of all types of chronic wounds, advanced wound dressings and studies resulted in more study effects, more reliable estimates of mean effects and more statistical power. These differences in the design are likely to explain the differences in the meta-analytic results. Conclusion: A general superiority of advanced dressings on complete healing was shown. The generalizability of the results is limited by the methodological and report quality within studies identified, unexplained heterogeneity in study effects and possibly by publication bias.