Introduction: The introduction should provide a clear rationale for the manuscript in the context of current knowledge. Authors should explain the importance of the review and/or meta-analysis and why the current manuscript is considered necessary (if the paper is an update of a previous review, this should be stated, and the previous paper cited). If discussing interventions, authors should include details, such as, how interventions might work. Authors should ensure their introduction explicitly states the objective/ question addressed by the manuscript.
Methods: Authors should ensure their methods section includes details of the eligibility criteria for inclusion/exclusion; information resources searched and when they were accessed; the search strategy used; the selection and data collection process; how the study was assessed for potential bias; the effect measures used and how it was determined which measure was used for each outcome; statistical analysis used and supporting information for why specific analysis was chosen; a discussion of methods used to assess risk of bias due to missing data; and a description of how confidence in the data was assessed.
Results: Authors should provide a detailed overview of the search and selection process and are requested to provide a flow diagram to support this description; they should explain the exclusion of studies, which may appear to meet inclusion criteria but were excluded from analysis. Each study included in the analysis should be cited, its characteristics and risk-of-bias assessment presented. For each outcome authors are asked to present, for every study: a summary of statistics, an effect estimate and its precision using tables and/or plots to support this information. Authors are reminded to ensure they present results of all prespecified outcomes and provide results of any investigation into variability in the data.
Discussion: The discussion section should place the results of this review into context allowing readers to interpret its findings. Authors need to consider the limitations of the evidence of their review and any review processes used before discussing implications of the review and how it relates to potential policy, practice and future research.