Background: To critically assess the evidence of modified xiaoyao san (MXS) for treating functional dyspepsia (FD).
Methods: Systematic literature searches were carried out on the Medline database, CNKI database, Wanfang Data, VIP Information and the Cochrane Library. Reference lists located were checked for further relevant publications. Experts in the field and manufacturers of identified products were contacted for unpublished material. Studies were selected according to predefined inclusion and exclusion criteria. All randomized clinical trials of MXS for treating FD were included. Study selection, data extraction and validation were carried out by at least two reviewers with disagreements being settled by discussion. Weighted means and 95% confidence intervals were calculated and sensitivity analyses were carried out.
Results: Thirty-three potentially relevant articles were retrieved for further evaluation. Fourteen were suitable for inclusion in the meta-analysis. There was evidence that MXS compared with prokinetic drugs reduced symptoms (odds ratio 3.26, 95% CI 2.24 to 4. 47). There was evidence that MXS + prokinetic drugs compared with prokinetic drugs reduced symptoms (odds ratio 4.32, 95% CI 2.64 to 7.08).
Conclusion: MXS appears to be more effective compared to prokinetic drugs in the treatment of FD and no serious side-effects were identified. However, the evidence remains weak due to publication bias and methodological flaws, which may amplify the therapeutic benefit of MXS.