DOSage of Exercise for chronic low back pain disorders (DOSE): protocol for a systematic review with dose-response network meta-analysis.

Chronic low back disorders are the leading cause of direct and indirect healthcare burden globally. Exercise training improves pain intensity, mental health and physical function. However, the optimal prescription variables are unknown. We aim to compare the efficacy of various exercise dosages for chronic low back disorders to identify the optimal prescription variables. Six databases (Medline, SPORTDiscus, CINAHL, PsycINFO, EMBASE and CENTRAL), trial registries (ClinicalTrials.gov and WHO International Clinical Trials Registry Platform) and reference lists of prior systematic reviews will be searched, and we will conduct forward and backward citation tracking. We will include peer-reviewed randomised controlled trials (individual, cluster or cross-over trials) published in English or German language comparing exercise training to other exercise training or non-exercise training interventions (conservative, non-surgical, non-pharmacological, non-invasive treatments, placebo, sham, usual/standard care, no-treatment control, waitlist control) in adults with chronic low back disorders. Outcomes will include pain intensity, disability, mental health, adverse events, adherence rate, dropout rate and work capacity. Version 2 of the Cochrane risk-of-bias tool will be employed. The dose will be categorised as cumulative dose (total and weekly minutes of exercise training) and individual dose prescription variables (intervention duration, session duration, frequency and intensity). Dose-response model-based network meta-analysis will be used to assess the comparative efficacy of different exercise doses to determine a dose-response relationship. The certainty of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation. Information about optimal exercise training dosage will help in enhancing treatment outcomes.