PRISMA (Preferred Reporting Items for Systematic Reviews and Meta Analyses)

PRISMA is a reporting guideline that provides a standardized checklist and flow diagram for the transparent and complete reporting of systematic reviews and meta analyses. The PRISMA 2020 update, which replaced the original 2009 statement, kept a 27 item checklist (several items now have sub items), integrated the PRISMA for Abstracts checklist, added items on certainty of evidence, competing interests and the availability of data and code, asked authors to report any automation tools used in study selection, and revised the flow diagram.

Systematic reviews are used to inform clinical guidelines, health policy, and future research priorities. If they are poorly reported, readers cannot evaluate the rigor of the review or replicate its methods. PRISMA addresses this problem by establishing a minimum standard for what information should be included. Journal editors increasingly require PRISMA compliance as a condition of publication, and PRISMA-P (the protocol extension) sets out what a review protocol should report. By ensuring transparency, PRISMA enables readers to assess the credibility of review findings and identify potential sources of bias. Over the past decade, PRISMA has become one of the most widely cited reporting guidelines in health research.

The PRISMA checklist covers the essential elements of a systematic review across all sections of the manuscript. The title should identify the report as a systematic review. The abstract should follow a structured format. The introduction should describe the rationale and give an explicit statement of the objectives or questions the review addresses, often framed around participants, interventions, comparators, and outcomes.

The methods section requires detailed reporting of eligibility criteria, information sources (databases, registries, and other sources searched), the full search strategies for all databases, registers and websites searched (including any filters and limits), the study selection process (including the number of reviewers and how disagreements were resolved), data collection procedures, risk of bias assessment tools used, the synthesis methods (including how heterogeneity was assessed and any quantitative synthesis methods), and any procedures for assessing certainty of evidence (such as GRADE).

The results section should present the study selection process through the PRISMA flow diagram, characteristics of included studies, risk of bias results, individual study results, and synthesis findings. The discussion should address the summary of evidence, limitations of both the included studies and the review itself, and implications for practice and research.

PRISMA extensions exist for specific review types, including PRISMA for Network Meta Analyses, PRISMA for Diagnostic Test Accuracy reviews, PRISMA for Scoping Reviews, and PRISMA for Individual Participant Data reviews. Each extension modifies the checklist to address the unique reporting needs of that review type.

Apply PRISMA when writing up any systematic review or meta analysis for publication. Use it as a checklist during the writing process to ensure no essential information is omitted. PRISMA-P should be used when developing and registering a systematic review protocol. For review types with dedicated extensions, use the appropriate extension. PRISMA is not a quality assessment tool for judging the methodological quality of a review; it is a reporting guideline that helps authors present their work completely and transparently.

A common mistake is treating PRISMA as a methods guide rather than a reporting standard. PRISMA tells authors what to report but does not prescribe how to conduct the review. Another frequent error is completing the checklist superficially, stating that items were addressed without providing the necessary detail (for example, writing "databases were searched" without listing which databases or providing the search strategy). Researchers sometimes use the 2009 version rather than the 2020 update, missing important additions such as reporting on automation tools and certainty of evidence. Finally, some authors include a PRISMA flow diagram but provide numbers that do not reconcile across stages, undermining the transparency the diagram is intended to provide.

A team conducting a systematic review of telehealth interventions for diabetes management uses the PRISMA 2020 checklist during manuscript preparation. They report their search across five databases with the full search strategy for each database reproduced in the appendix, document that 3,412 records were identified, describe the two reviewer screening process with a kappa statistic for agreement, present a PRISMA flow diagram showing 28 studies included from 3,412 records, use GRADE to assess certainty across outcomes, and note in the limitations section that non English publications were excluded. The completed PRISMA checklist is submitted as a supplementary file.