The PRISMA 2020 guidelines are the current international standard for reporting systematic reviews and meta-analyses. Published by Page et al. in 2021, the PRISMA 2020 statement replaced the original PRISMA 2009 guidelines that had governed systematic review reporting for over a decade. Every researcher conducting a systematic review must understand these guidelines, not as an afterthought during manuscript preparation, but as a framework that shapes the entire review process from protocol to publication.
In every systematic review we deliver, PRISMA 2020 compliance is our baseline, not an optional extra. Having prepared hundreds of PRISMA-compliant manuscripts, we have seen firsthand how adherence to these reporting standards reduces desk rejections, satisfies peer reviewers, and accelerates the path to publication.
What Are the PRISMA 2020 Guidelines?
The distinction between a reporting guideline and a methodological guide matters. PRISMA 2020 does not tell you how to conduct a systematic review. It tells you what to report about how you conducted one. The Cochrane Handbook for Systematic Reviews of Interventions (Higgins et al., 2023) provides methodological guidance; PRISMA 2020 ensures that the methods you used are communicated transparently to readers, peer reviewers, and editors.
PRISMA 2020 applies to systematic reviews of interventions, exposures, diagnostic test accuracy, prognosis, and other research questions. It applies whether or not the review includes a meta-analysis. The guidelines are relevant across disciplines, from medicine and public health to psychology, education, and environmental science, wherever systematic reviews are conducted and published.
The EQUATOR Network maintains PRISMA 2020 as part of its library of reporting guidelines and recommends its use by authors, editors, and peer reviewers worldwide. Journals that endorse EQUATOR guidelines, which includes the majority of biomedical journals indexed in MEDLINE, expect submitted systematic reviews to comply with PRISMA 2020.
The 27 Checklist Items Explained
The PRISMA 2020 checklist contains 27 items organized across seven sections. Each item specifies a reporting element that should be present in your manuscript, with the corresponding section (title, abstract, introduction, methods, results, discussion, or other information) indicating where the information belongs.
Section 1: Title (Item 1)
Item 1, Title: Identify the report as a systematic review. The title must explicitly state that the manuscript is a systematic review, a meta-analysis, or both. Titles that describe the topic without identifying the study design fail this item. A compliant title reads something like "Effectiveness of cognitive behavioral therapy for insomnia: a systematic review and meta-analysis" rather than simply "Cognitive behavioral therapy for insomnia."
Section 2: Abstract (Item 2)
Item 2, Abstract: Provide a structured summary including background, objectives, data sources, study eligibility criteria, participants, interventions, study appraisal and synthesis methods, results, limitations, conclusions, and registration information. Most journals require structured abstracts for systematic reviews, and PRISMA 2020 specifies what each section should contain.
Section 3: Introduction (Items 3-4)
Item 3, Rationale: Describe the rationale for the review in the context of existing knowledge. This means explaining why the review is needed, whether previous reviews are outdated, conflicting, or nonexistent.
Item 4, Objectives: Provide an explicit statement of the review question using the PICO framework (Population, Intervention, Comparator, Outcome) or an appropriate alternative.
Section 4: Methods (Items 5-16)
The methods section contains 12 items, nearly half the entire checklist, reflecting PRISMA 2020's emphasis on methodological transparency. This is where most reporting failures occur, and where compliance matters most for peer review.
Item 5, Eligibility criteria: Specify the inclusion and exclusion criteria for the review, including study characteristics (PICO elements) and report characteristics (publication date, language, publication status).
Item 6, Information sources: Describe all information sources searched, including databases, registers, websites, organizations, and reference lists. Specify the date of the last search for each source.
Item 7, Search strategy: Present the complete search strategy for at least one database, including any filters and limits, so that it can be reproduced. This is a new emphasis in PRISMA 2020, full reproducibility of the search.
Item 8, Selection process: Specify the methods used to decide whether a study meets the eligibility criteria, including how many reviewers screened each record and each report, whether they worked independently, and what software or automation tools were used.
Item 9, Data collection process: Specify the methods used to collect data from reports, including how many reviewers collected data, whether they worked independently, any processes for obtaining or confirming data from study investigators, and any automation tools used.
Item 10, Data items: List and define all outcomes and other variables for which data were sought, specifying any assumptions and simplifications made.
Item 11, Study risk of bias assessment: Specify the methods used to assess risk of bias in included studies, including which tool was used (such as RoB 2 for randomized trials or ROBINS-I for non-randomized studies), how many reviewers assessed each study, and whether they worked independently.
Item 12, Effect measures: Specify for each outcome the effect measure used (risk ratio, odds ratio, mean difference, etc.) and how it was calculated.
Item 13, Synthesis methods: Describe the processes used to synthesize results, including the statistical model (fixed-effect or random-effects), the method for calculating the summary effect, methods for assessing heterogeneity (such as I-squared and tau-squared), any sensitivity analyses, and subgroup analyses planned a priori. This item also covers narrative synthesis approaches when meta-analysis is not possible.
Item 14, Reporting bias assessment: Describe any methods used to assess the risk of reporting bias across studies, such as funnel plots, Egger's test, or trim-and-fill analysis.
Item 15, Certainty assessment: Describe any methods used to assess certainty (or confidence) in the body of evidence for each outcome, such as the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach. This is a new requirement in PRISMA 2020 that was not present in the 2009 version.
Item 16, Study registration and protocol: Provide registration information for the review, including the register name and registration number, and indicate where the review protocol can be accessed. If a protocol was prepared, indicate where it can be accessed and list any amendments to the protocol.
Section 5: Results (Items 17-23)
Item 17, Study selection: Give the total number of records identified, screened, assessed for eligibility, and included, with reasons for exclusion at each stage. This information is presented in the PRISMA flow diagram.
Item 18, Study characteristics: Cite each included study and present its characteristics, including the PICO elements, study design, sample size, and funding source.
Item 19, Risk of bias in studies: Present the results of the risk of bias assessment for each included study and across studies for each outcome.
Item 20, Results of individual studies: For all outcomes, present for each study a summary of the data, the effect estimate with confidence interval, and any supporting visual display such as a forest plot.
Item 21, Results of syntheses: For each synthesis, present the summary result with confidence interval and measures of statistical heterogeneity. Present any assessments of heterogeneity causes (subgroup analyses, meta-regression). If meta-analysis was not conducted, present structured summaries of the individual study results.
Item 22, Reporting biases: Present any assessments of risk of reporting bias, including results of funnel plots or statistical tests.
Item 23, Certainty of evidence: Present assessments of certainty in the body of evidence for each outcome assessed, typically using GRADE summary of findings tables.
Section 6: Discussion (Items 24-26)
Item 24, Discussion: Provide a general interpretation of results in the context of other evidence. Discuss the limitations of the evidence included in the review and limitations of the review process itself.
Item 25, Implications: Discuss implications for practice, policy, and future research.
Item 26, Other information: Provide information about sources of financial or non-financial support for the review, declare any conflicts of interest, and state the availability of data, code, and other materials used in the review.
Section 7: Other Information (Item 27)
Item 27, Registration and protocol: Provide the registration number and where the registration and protocol can be accessed. While this overlaps with Item 16 in the methods, Item 27 ensures this information is also presented in the final sections of the manuscript for quick reference.
