Methods

Searching

The information sources, in detail (e.g., databases, registers, personal files, expert informants, agencies, hand-searching), and any restrictions (years considered, publication status, language of publication)

Selection

The inclusion and exclusion criteria (defining population, intervention, principal outcomes, and study design)

Validity assessment

The criteria and process used (e.g., masked conditions, quality assessment, and their findings)

Data abstraction

The process or processes used (e.g., completed independently, in duplicate)

Study characteristics

The type of study design, participants’ characteristics, details of intervention, outcome definitions, &c, and how clinical heterogeneity was assessed

Quantitative data Synthesis

The principal measures of effect (e.g., relative risk), method of combining results (statistical testing and confidence intervals), handling of missing data; how statistical heterogeneity was assessed; a rationale for any a-priori sensitivity and subgroup analyses; and any assessment of publication bias

Results

Trial flow

Provide a meta-analysis profile summarizing trial flow (see figure)

Study characteristics

Present descriptive data for each trial (e.g., age, sample size, intervention, dose, duration, follow-up period)

Quantitative data synthesis

Report agreement on the selection and validity assessment; present simple summary results (for each treatment group in each trial, for each primary outcome); present data needed to calculate effect sizes and confidence intervals in intention-to-treat analyses (e.g. 2×2 tables of counts, means and SDs (standard deviations), proportions)

Discussion

Summarize key findings; discuss clinical inferences based on internal and external validity; interpret the results in light of the totality of available evidence; describe potential biases in the review process (e.g., publication bias); and suggest a future research agenda

Quality of reporting of meta-analyses