Herbal medicine for cervicogenic dizziness A protocol for a systematic review and meta-analysis

Background: Herbal medicines are empirically used to treat cervicogenic dizziness. However, till date there have been no systematic review to evaluate the efficacy and safety of these medicines. Therefore, this study protocol describes the methods for evaluating the efficacy and safety of herbal medicine for cervicogenic dizziness. Methods and analysis: The following electronic academic databases will be searched up to December 2019 without language or publication status restrictions: Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), and the Cochrane Central Register of Controlled Trials (CENTRAL), together with Korean, Chinese, and Japanese databases. Any randomized controlled trials related to herbal medicine for cervicogenic dizziness will be included. The functional outcomes and the vertebrobasilar artery hemodynamic states will be evaluated as primary outcomes. The total effective rate, hematological conditions, and adverse events will be assessed as secondary outcomes. Study selection, data extraction, quality assessment of studies, and qualitative evaluation of clinical evidence will be performed by 2 independent reviewers. The methodological quality of the included studies will be evaluated using a revised Cochrane risk-of-bias tool for randomized trials. The strength of evidence from the included data will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach. Data synthesis will be performed as either a fixed-effects or a random-effects model using Review Manager software version 5.3. The results will be reported as a risk ratio for dichotomous outcomes and as a mean difference or standardized mean difference for continuous outcomes. Ethics and dissemination: No ethical approval is required since the individual clinical information of the patient is not used. The findings of this systematic review will be disseminated through the peer-reviewed publications or conference presentations. Review Registry Unique Identifying Number: reviewregistry1036.