What are the most effective behaviour change techniques to promote physical activity and/or reduce sedentary behaviour in inactive adults? A systematic review protocol

Introduction: Large proportions of the population are not meeting recommended levels of physical activity and have increasingly sedentary lifestyles. Low levels of physical activity are predictive of poor health outcomes and time spent sedentary is related to a host of risk factors independently of physical activity levels. Building an evidence base of the best approaches to intervene in the lifestyles of inactive individuals is crucial in preventing long-term disease, disability and higher mortality rates. Methods and analysis: Systematic searches will be conducted on all relevant databases (eg, PubMed, Scopus, CINAHL, PsycINFO). Studies will be included if they assess interventions aimed at changing physical activity or sedentary behaviour levels in adults (over 18) who are inactive and do not suffer from chronic conditions. Studies must also be randomised controlled trials (RCTs), have a primary outcome of physical activity or sedentary behaviour, and measure outcomes at least 6 months after intervention completion. Studies will be coded using the Behaviour Change Technique (BCT) taxonomy v1 and Template for Intervention Description and Replication (TIDieR) guidelines. 2 reviewers will independently screen full-text articles and extract data on study characteristics, participants, BCTs, intervention features and outcome measures. Study quality will also be assessed independently by 2 reviewers using the Cochrane risk of bias tool. A meta-analysis will be considered if there is sufficient homogeneity across outcomes. GRADE criteria will be used to assess quality of evidence. Dissemination: This will be the first review to systematically appraise interventions aimed at changing the physical activity or sedentary behaviour of inactive individuals using RCT designs with a 6-month follow-up post-intervention. This review will better inform intervention designers targeting inactive populations and inform the design of a future complex intervention.