PRISMA 2020 vs 2009 flow diagram
Updated 2026-10-12
The PRISMA flow diagram was redesigned when the guideline was updated in 2020. This guide compares the two versions box by box and shows how to move an older diagram onto the current layout.
The short version
- The 2009 diagram had four phases: Identification, Screening, Eligibility and Included. The 2020 diagram has three sections: Identification, Screening and Included.
- PRISMA 2020 separates records, reports and studies. The 2009 diagram used "records" and "full-text articles" and did not distinguish a study from the papers that report it.
- Searches of databases and registers are now shown separately from other methods such as websites, organisations and citation searching.
- There are new boxes for records removed by automation tools and for reports that could not be retrieved.
- The separate boxes for qualitative synthesis and quantitative synthesis (meta-analysis) are gone.
- There is one template in 2009 and four in 2020, including two for updated reviews.
Box by box comparison
| Stage | PRISMA 2009 | PRISMA 2020 |
|---|---|---|
| Search results | Records identified through database searching | Records identified from databases and from registers, ideally with a count for each one |
| Other sources | Additional records identified through other sources, as one number | A separate column for websites, organisations, citation searching and similar methods, with its own retrieval and eligibility boxes |
| Before screening | Records after duplicates removed | Records removed before screening: duplicates, records marked ineligible by automation tools, and other reasons |
| Title and abstract | Records screened; records excluded | Records screened; records excluded |
| Retrieval | Not shown | Reports sought for retrieval; reports not retrieved |
| Full text | Full-text articles assessed for eligibility; full-text articles excluded, with reasons | Reports assessed for eligibility; reports excluded, with a count for each reason |
| Included | Studies included in qualitative synthesis; studies included in quantitative synthesis (meta-analysis) | Studies included in review; reports of included studies |
| Updates | No dedicated layout | A "previous studies" column and totals for new and previous studies |
Why the diagram changed
Review methods moved on between 2009 and 2020. Reviewers now routinely search trial registers, use software to help with screening, and find evidence through citation tracking and websites. The 2009 layout had nowhere to show any of that. It also hid a real source of confusion: a single trial is often reported in several papers, so "articles" and "studies" are different counts. The 2020 diagram makes each of those things visible. The full reasoning is in the PRISMA 2020 statement (Page et al., BMJ 2021;372:n71), which replaced the 2009 statement (Moher et al., PLoS Medicine 2009;6(7):e1000097).
Which version should you use?
Use PRISMA 2020 for any review you are writing now. Most journals that endorse PRISMA expect the current version, and peer reviewers do check. The 2009 diagram is only appropriate if you are following a protocol or journal instruction that explicitly names it. If you are updating a review that was first published with a 2009 diagram, report the update with the PRISMA 2020 updated review template.
How to convert a 2009 diagram to PRISMA 2020
- Split the search results. Go back to your search log and get the count for each database and register, in place of one combined number.
- Separate other sources. Move records from websites, organisations and citation searching into the other methods column. If you had none, use the databases and registers only template.
- Turn "records after duplicates removed" around. The 2020 box reports how many were removed, not how many were left. Subtract to get the duplicates removed.
- Add retrieval. Count the full texts you tried to get and the ones you could not obtain. In 2009 these were often folded into the exclusions.
- Rename full-text articles as reports and keep a count for each exclusion reason.
- Replace the two synthesis boxes. Give the number of studies included and the number of reports of those studies.
Then check that each box reconciles with the one above it. The worked example shows the arithmetic, and the generator lays out the 2020 boxes for you once the numbers are in.
Quick answers
Can I still use the PRISMA 2009 flow diagram?
Only if your journal or protocol specifically asks for it. For new reviews, use PRISMA 2020, which replaced the 2009 version.
Where did the meta-analysis box go?
PRISMA 2020 removed the separate qualitative and quantitative synthesis boxes. The final box reports the studies included in the review. If only some were pooled in a meta-analysis, give that number in your results text.
Is the PRISMA 2020 flow diagram mandatory?
PRISMA is a reporting guideline, not a law, but many journals require authors to follow it, and item 16a of the checklist asks for the selection process to be reported, ideally with a flow diagram.
Source of the flow diagram wording: Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. doi:10.1136/bmj.n71. Licensed CC BY 4.0. This site is independent and not affiliated with the PRISMA or EQUATOR Network groups.