PRISMA Methodology
for Systematic Review

PRISMA – Preferred Reporting Items for Systematic reviews and Meta-Analyses – was born from the desire to fix the inconsistencies and lack of transparency in the reporting of systematic reviews and meta-analyses. The PRISMA 2020 systematic review guideline presents a minimum set of items that authors and reviewers must include in their reviews or analyses.

Using the PRISMA methodology is quite straightforward when you have the necessary information; completing the PRISMA checklist and flow diagram will tell you which items to report in your methods section, as well as how to present the information that comprises the rest of the study paper.

The PRISMA Checklist

What is the PRISMA checklist? It is a 27-item checklist developed by experienced authors and reviewers. The checklist addresses the introduction, methods, results, and discussion sections of a systematic review report, and directs reviewers and authors to understand the fundamental items that must be included in their reviews. Many minor but crucial details go into a quality systematic review – be sure to check out our PRISMA statement example.

The PRISMA Flow Diagram

The PRISMA flow diagram is a visual representation of the reviewers’ process for locating published data, and documents what investigators chose to include in the review. The diagram quickly lets readers know how many studies were screened, how many were included in the review, and what criteria were used.

Properly created flow diagrams contain four phases – identification, screening, eligibility, and inclusion – based on the original PRISMA flow diagram. These can help readers and reviewers assess the logical stages of the process, as well as define the boundaries of the research. Use the steps below to learn how to do a PRISMA flow diagram:

1. Save a copy of the PRISMA 2020 flow diagram template; it can be downloaded from the PRISMA website.
2. Conduct your database search through abstract and citation searches (eg, using PubMed, Scopus). Save the final number of articles for each database and enter this information into your citation management tool (eg, Paperpile, Zotero, Microsoft Excel, or Google Sheets).
3. Remove any articles that appear more than once in the searches. Input the number of duplicate records removed in the “duplicate records removed” subheading of the “records removed before screening” box of the flow diagram.
4. Record the number of articles that you will screen for review as “records screened.” This number is calculated by subtracting the “duplicate records removed” box from the number of records identified.
5. Screen the titles and abstracts of articles that are relevant to the topic of your review – the articles that appear relevant are known as inclusions.
6. Record the number of articles excluded from the title/abstract screening in the box to the right titled, “records excluded.”
7. Subtract the number of exclusions from the total number of screened records to see the number of articles for use in the review, and to record this number.
8. Attempt to collect the full text of these articles, and record the number of articles you were unable to find in “reports not retrieved.”
9. Record the number of articles that received full-text screening as “reports screened for eligibility.” Full-text screening of included articles involves the complete reading of articles to determine their eligibility for inclusion in your review.
10. After reviewing all the articles, record the total number of articles you excluded in the box titled “reports excluded.” The PRISMA 2020 flow diagram requires that you group the reasons why these articles were excluded. Some common reasons for exclusions include wrong setting, wrong demography, wrong patient population, and wrong intervention.
11. The final step is to record the number of eligible articles featured in the review as “total studies included in review.” To find this number, subtract the number of records excluded during the eligibility review of full texts (step 10) from the total number of articles reviewed for eligibility (step 9).