A PRISMA flow diagram provides a transparent record of how you searched for and selected literature in a systematic or scoping review. To create one accurately, you need to choose the correct template, distinguish records, reports and studies, and ensure every number and exclusion reason can be traced through the review process.

What Is A PRISMA Flow Diagram And Which Template Should You Use?

PRISMA stands for Preferred Reporting Items for Systematic reviews and Meta-Analyses. It is a reporting standard designed to provide a transparent, reproducible record of how you searched for and selected literature.

For systematic and scoping reviews, a PRISMA flow diagram is a standard expected component of your submission. For other review types, it is not a formal requirement and may be inappropriate depending on the search and selection process. However, a simplified or modified version can still clearly communicate your review process.

The official PRISMA website provides four flow diagram templates. Two are for systematic reviews that update a previous review, while the other two are for new reviews. One covers databases and registers only. The other includes databases, registers and other sources, including citation chaining, grey literature and other searches outside academic databases.

There is also a web application for generating a customised diagram, although the Word template is easier to edit directly and import into a dissertation.

How Do You Populate A PRISMA Flow Diagram Correctly?

Before populating the diagram, distinguish between a record, report and study. A record is what a database returns from a search. A report is a document, such as a journal article or dissertation. A study is the actual investigation. One study can have multiple reports.

In the identification stage, record each database separately and give the number of results returned. If you searched PubMed, Scopus and CINAHL, each should have its own value, with the total calculated from these results. Study registers should also be recorded separately.

During screening, remove duplicates and record the number of unique records screened. Records excluded at title and abstract stage require a single total.

At eligibility stage, record reports sought for retrieval, reports not retrieved and reports assessed for eligibility. Full-text exclusions require specific reasons, each with its own number.

For other sources, record citation searching, grey literature or handsearching separately. The final included box counts studies, so multiple reports relating to the same study should be counted as one study.

What Are The Most Common PRISMA Flow Diagram Mistakes?

The most common mistakes are avoidable if you check the diagram carefully before submission.

1. Numbers that do not reconcile. Every number must be traceable through the diagram. Check the arithmetic from the top to the bottom before submitting.

2. Confusing studies and reports. First record the number of reports, meaning the articles or other documents. Then identify how many studies those reports represent. Multiple reports can come from the same study.

3. Vague exclusion reasons. At full-text eligibility stage, each exclusion reason needs its own number, and the reasons must add up to the total excluded figure. Reasons such as “not relevant” do not explain how your criteria were applied. Use specific reasons such as wrong population, wrong intervention or wrong study design.

4. Missing boxes. Do not copy a published flow diagram and assume it contains all the rows you need. Published diagrams have already been customised. Start with the official Word template.

5. Formatting problems. Once your numbers are final, take a screenshot of the completed diagram and insert it as an image into your dissertation. Keep the editable version separately in case amendments are needed.

The annotated PRISMA template is available in the resource hub if you want a visual reference while completing your own diagram.

If your flow diagram is complete but you need help checking the wider methodology, including your search strategy and inclusion criteria, you can find out more about my research support services.