Efficacy of electro-acupuncture and manual acupuncture versus sham acupuncture for knee osteoarthritis: statistical analysis plan for a randomized controlled trial

BACKGROUND: Acupuncture is widely used for knee osteoarthritis (KOA), despite contradictory evidence. This study is designed to determine the efficacy of electro-acupuncture and manual acupuncture versus sham acupuncture for KOA. METHODS/DESIGN: This is a multi-center three-arm randomized controlled trial. It will enroll 480 participants with KOA in China. Participants will be randomly assigned 1:1:1 to receive 24 sessions of electro-acupuncture, manual acupuncture, or sham acupuncture over 8 weeks. The primary outcome is the response rate, which is the proportion of patients who achieve the minimal clinically important improvement in pain and function at 8 weeks. The primary outcome will be analyzed using the Z-test with the intention-to-treat set. Secondary outcomes include pain, function, global patient assessment, and quality of life. Full details of the statistical analysis plan for the primary and secondary outcomes will be described in this article. The statistical analysis plan was written and submitted without knowledge of the study data. DISCUSSION: The data will be analyzed according to this pre-specified statistical analysis plan to avoid data-driven analysis and to enhance the transparency of the trial. The aim of the trial is to provide high-quality evidence on the efficacy of acupuncture for KOA. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03366363. Registered on 20 November 2017.