Background: This systematic review protocol describes the methods that will be used to evaluate the efficacy and safety of herbal medicine in treating traumatic brain injury.
Methods and analysis: The following electronic databases will be searched up to December 2018 without language or publication status restrictions: Medline, EMBASE, the Cochrane Central Register of Controlled Trials, Allied and Complementary Medicine Database, and Cumulative Index to Nursing and Allied Health Literature. We will also search Korean, Chinese, and Japanese databases. Any randomized controlled trials related to herbal medicine for traumatic brain injury will be included. The functional outcome, consciousness state, morbidity, and mortality will be assessed as primary outcomes. The quality of life, adverse events, and total effective rate will be evaluated as secondary outcomes. Two researchers will independently perform the study selection, data extraction, assessment of study quality, and evaluation of the quality of evidence for the main findings. Data synthesis and analysis will be performed using RevMan version 5.3. The results will be expressed as a risk ratio for the binary outcome and as the mean difference or standardized mean difference for a continuous outcome. We will synthesize the data by either fixed effects or random effects model according to a heterogeneity test or the number of studies included in the meta-analysis. The methodological quality of the included studies will be evaluated using the Cochrane Collaboration's risk of bias tool. The quality of evidence for each main outcome will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach.
Ethics and dissemination: Ethical approval is not required because individual patient data are not included. The findings of this systematic review will be disseminated through a peer-reviewed publication or conference presentations.
Prospero registration number: CRD42018116559.