Eunkyosan for treatment of the common cold: A protocol for the systematic review of controlled trials.

INTRODUCTION: Eunkyosan (EKS) is widely used for common colds in East Asian countries. Many clinical trials assessing the efficacy and safety of EKS formula for the treatment of common colds have been reported. This review will assess the clinical evidence for and against the use of EKS formula as a treatment for common colds.

METHODS AND ANALYSIS: Fourteen databases will be searched from inception until March 2018. We will include randomized controlled trials (RCTs) assessing EKS decoctions for any type of common cold. All RCTs of decoctions or modified decoctions will be included. The methodological qualities of the RCTs will be assessed using the Cochrane Collaboration tool for assessing risk of bias, while confidence in the cumulative evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument.

ETHICS AND DISSEMINATION: This systematic review will be published in a peer-reviewed journal and will also be disseminated electronically and in print. The review will be updated to inform and guide healthcare practices.Registration number: CRD42018087694.