Integrative medicine (East Asian herbal medicine combined with conventional medicine) for psoriasis: A protocol for systematic review and meta-analysis

Background: Psoriasis is a chronic, inflammatory, autoimmune skin disease. The aim of this review is to systematically evaluate the efficacy and safety of integrative medicine (East Asian herbal medicine combined with conventional medicine) used to treat inflammatory skin lesions of psoriasis. Methods: A comprehensive literature search will be conducted in 3 English databases (PubMed, Cochrane Library, and Embase), 4 Korean databases (Korean Studies Information Service System, Research Information Service System, Oriental Medicine Advanced Searching Integrated System, and Korea Citation Index), 2 Chinese databases (Chinese National Knowledge Infrastructure Database and Wanfang data), and 1 Japanese database (Citation Information by National Institute of Informatics) for randomized controlled trials from their inception until July 29, 2021. Statistical analysis will be performed using R version 4.1.2 and the R studio program using the default settings of the "meta" and "metafor" packages. The primary outcome will be an improvement in the psoriasis area severity index. All outcomes will be analyzed using a random-effects model to produce more statistically conservative results. If heterogeneity is detected in the study, the cause will be identified through sensitivity, meta-regression, and subgroup analyses. Methodological quality will be assessed independently using the revised tool for the risk of bias in randomized trials, version 2.0. The overall quality of evidence will be evaluated according to the Grading of Recommendations Assessment, Development, and Evaluation pro framework. Results: This study will review all available trials on the same subject and arrive at a more statistically robust conclusion based on a sufficient sample size of participants and additional analysis using data mining techniques will be performed on intervention prescription information in clinical studies collected according to rigorous criteria. Conclusion: We believe that this study will provide useful knowledge on managing inflammatory skin lesions of psoriasis vulgaris using integrative medicine using East Asian herbal medicine.