Data extraction and management
Data will be extracted independently by two review authors using a customised form, piloted prior to use. This will be used to extract relevant data on methodological issues, eligibility criteria, interventions (including the number of participants treated, intervention provider) and study design, study duration, follow-up, comparisons, outcome measures, results, withdrawals and adverse events.
Intervention content will be coded according to the behaviour change technique taxonomy of 93 hierarchically clustered techniques . Two qualified coders will independently code behaviour change techniques. Kappa and percentage disagreement will be calculated, the two reviewers will meet to resolve any discrepancies, with third party adjudication if required.
In the case of multiple publications of the same study, we will, where possible, extract and combine all of the available data, in case of doubt; the original publication will be given priority. Where data seems to be missing from a study this will, if possible, be obtained through correspondence with the study authors. A table showing the characteristics of the included and excluded studies will be created