What it shows
The flow diagram from the PRISMA 2020 statement, redrawn as a vector, in the version for new systematic reviews which included searches of databases, registers and other sources. It follows records through three stages: identification, screening and included.
It keeps the template’s wording and UK spellings, and both of its footnotes; every count is left blank. The version for reviews that searched databases and registers only is the left column on its own. The PRISMA 2020 statement replaces the PRISMA 2009 statement.
How to read it
The left column starts with records identified from databases and registers; duplicates and other records removed before screening branch off to the right.
Records screened lead to reports sought for retrieval and then to reports assessed for eligibility. At each step, the box to the right records what dropped out, with reasons at the eligibility step.
The right column handles other methods (websites, organizations, citation searching). Those records have no “Records screened” box; they go straight to reports sought for retrieval, then eligibility.
Both columns end in the same box: studies included in the review, and the reports of those studies.
What each box records
- Identification: records identified from databases and from registers; records removed before screening (duplicates, marked ineligible by automation tools, other reasons).
- Screening: records screened and excluded; reports sought for retrieval and not retrieved; reports assessed for eligibility and excluded, with reasons.
- Other methods: records identified from websites, organizations and citation searching; reports sought, not retrieved, assessed and excluded.
- Included: studies included in the review, and reports of included studies.
Ways to use it in teaching
Give students the search log of a small published review and have them fill in the counts.
Compare it with the PRISMA 2009 diagram (Moher et al. 2009) to show what PRISMA 2020 added: registers, automation tools, and a separate retrieval and eligibility route for other methods (the 2009 diagram counted other sources at identification only).
In a research methods course, use it to make the difference between a record, a report and a study concrete.
For how a search strategy feeds the numbers in a diagram like this, see our guide to building a literature search strategy.
Sources
- Moher, D., Liberati, A., Tetzlaff, J., Altman, D. G., & The PRISMA Group. (2009). Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Medicine, 6(7), e1000097. https://doi.org/10.1371/journal.pmed.1000097
- Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., Brennan, S. E., Chou, R., Glanville, J., Grimshaw, J. M., Hróbjartsson, A., Lalu, M. M., Li, T., Loder, E. W., Mayo-Wilson, E., McDonald, S., . . . Moher, D. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, n71. https://doi.org/10.1136/bmj.n71
- PRISMA. (n.d.). PRISMA 2020 flow diagram. https://www.prisma-statement.org/prisma-2020-flow-diagram
