The title must identify the report as a systematic review (and as a meta-analysis if applicable). The abstract must follow the PRISMA 2020 for Abstracts structure — objectives, eligibility criteria, information sources, risk of bias, synthesis methods, results, discussion, and registration. Reviewers will scan the abstract before opening the methods; an abstract that hides the review design or omits effect estimates is a red flag.
02Introduction — rationale and objectives
Describe the rationale for the review in the context of existing knowledge. Provide an explicit statement of the objective(s) or question(s) the review addresses, framed in PICO terms (or analogue) where appropriate. Vague rationales ("there is no review on this topic") without explaining why one is now needed are flagged.
03Methods — eligibility criteria
Specify the inclusion and exclusion criteria for the review and how studies were grouped for the syntheses. PICO is the standard framework — Population, Intervention or exposure, Comparator, Outcomes — plus design, timeframe, and language restrictions. Eligibility criteria that change between protocol and final review without justification is one of the clearest signs of post-hoc adjustment.
04Methods — information sources
Specify all databases, registers, websites, organizations, reference lists, and other sources searched or consulted to identify studies. Specify the date when each source was last searched or consulted. PubMed alone is not adequate for most reviews — at minimum reviewers expect MEDLINE/PubMed, Embase, and a trials registry (such as CENTRAL or ClinicalTrials.gov), plus grey-literature sources where relevant.
05Methods — search strategy
Present the full search strategies for all databases, registers, and websites, including any filters and limits used. PRISMA 2020 expects the full search syntax — typically in a supplementary file — not a paraphrased summary. Reviewers will check that the strategy was peer-reviewed (PRESS) or note its absence.
06Methods — selection process
Specify the methods used to decide whether a study met the inclusion criteria of the review, including how many reviewers screened each record and each retrieved report, whether they worked independently, and details of automation tools used in the process. Single-reviewer screening with no second check is flagged — duplicate independent screening is the standard.
07Methods — data collection process
Specify the methods used to collect data from reports, including how many reviewers collected data from each report, whether they worked independently, any processes for obtaining or confirming data from study investigators, and details of automation tools used. Conflicts in extracted data must be resolved by a documented process — typically discussion or third-reviewer adjudication.
List and define all outcomes for which data were sought and all other variables (such as participant and intervention characteristics, funding sources). Specify whether all results compatible with each outcome in each included study were sought (such as all measures, time points, analyses), and if not, the methods used to decide which results to collect. Selective outcome extraction is flagged.
09Methods — study risk of bias assessment
Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and details of automation tools used. Cochrane RoB 2 for RCTs and ROBINS-I for non-randomized studies are the modern defaults. "Quality varied across studies" without a structured tool is a major issue.
10Methods — effect measures and synthesis methods
Specify for each outcome the effect measure(s) used (such as risk ratio, mean difference). Describe the processes used to decide which studies were eligible for each synthesis. Describe any methods to tabulate or visually display results. Describe any methods used to synthesize results — for meta-analyses, specify the model (fixed vs. random effects), how statistical heterogeneity was assessed (such as I²), and how heterogeneity was explored (subgroup, meta-regression).
11Methods — reporting bias and certainty assessment
Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases). Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome — typically GRADE. Reviewers will look for this explicitly; reporting heterogeneity and precision alone does not substitute for certainty assessment.
12Results — study selection (with PRISMA flow diagram)
Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included, ideally using the PRISMA flow diagram. Cite studies that might appear to meet the inclusion criteria but which were excluded, and explain why. The flow diagram is effectively mandatory — manuscripts without it are flagged immediately.
13Results — study characteristics and risk of bias
Cite each included study and present its characteristics — typically in a single summary table. Present assessments of risk of bias for each included study, by domain, in a structured table or figure. Aggregate "overall study quality was good" statements without per-study, per-domain detail do not satisfy this item.
14Results — individual study results and syntheses
For each study, present for each outcome summary statistics (such as event counts) and an effect estimate with its precision (typically 95% CI), ideally using a forest plot. For each synthesis, present the summary estimate and its precision, and measures of statistical heterogeneity. Present results of all investigations of possible causes of heterogeneity among study results. Present results of all sensitivity analyses.
15Results — reporting biases and certainty of evidence
Present assessments of risk of bias due to missing results (arising from reporting biases) for each synthesis assessed. Present assessments of certainty (or confidence) in the body of evidence for each outcome assessed, typically in a GRADE summary-of-findings table. This is one of the most under-reported items in PRISMA-evaluated manuscripts.
16Discussion — interpretation and limitations
Provide a general interpretation of the results in the context of other evidence. Discuss any limitations of the evidence included in the review (such as risk of bias, indirectness, imprecision, inconsistency, publication bias). Discuss any limitations of the review processes used (such as language restrictions, single-reviewer extraction). Discuss implications for practice, policy, and future research.
17Other information — registration, support, conflicts, data availability
Provide registration information (such as PROSPERO registration number) and indicate where the protocol can be accessed. Describe and explain any amendments to information provided at registration or in the protocol. Describe sources of financial or non-financial support, and the role of the funders. Declare any competing interests. Report which of the following are publicly available and where: template data collection forms; data extracted from included studies; data used for all analyses; analytic code; any other materials used in the review. Unregistered systematic reviews are flagged.