Abstract
BACKGROUND: Disorders of the cervical spine are some of the costliest musculoskeletal conditions to manage globally. Joint mobilization and manipulation have been shown to be an effective treatment for neck pain. However, the generalizability and clinical translation depends on the nature of the trial designs that inform its use. The extent to which randomized control trials (RCTs) assessing manual therapy treatments for cervical spine disorders fall on the efficacy (explanatory) -effectiveness (pragmatic) spectrum often informs how the findings are translated into clinical practice. OBJECTIVE: The aim of this systematic review was to determine where RCTs of manual therapy for neck disorders fall on the efficacy-effectiveness spectrum. METHODS: A search of three electronic databases including PubMed, CINAHL, and CENTRAL were completed for trials published from inception to May 2023. RCTs in which joint mobilization or manipulation were used to treat cervical spine disorders were assessed on the effectiveness-efficacy spectrum using the Rating of Included Trials on the Efficacy-Effectiveness Spectrum (RITES) tool and risk of bias using the Revised Cochrane Risk of Bias tool. RESULTS: A total of 174 trials met eligibility. RITES domain two trial setting (71.3% vs 16.1%), domain three flexibility of intervention(s) (62.1% vs 23%), and domain four clinical relevance of experimental and comparison intervention(s) (51.7% vs 29.3%) all favored efficacy over effectiveness. Domain one participant characteristic(s) had a slightly greater emphasis on effectiveness compared to efficacy (36.8% vs 44.8%). Most studies (96%) had at least some risk of bias. CONCLUSION: Over half of the RCTs assessing the treatment effect of joint mobilization and manipulation for neck pain favor efficacy (explanatory) over effectiveness (pragmatic) designs. Future RCTs on this topic should consider a greater emphasis on pragmatic trial design components in order to better reflect real-world translation to clinical practice.