A PRISMA flow diagram example is a completed, filled-in version of the study selection figure that shows real numbers flowing from identification down to the included studies, and seeing one is the fastest way to understand what your own diagram should look like. A good example demonstrates three things at once: the boxes are populated with database-specific counts, the arithmetic reconciles from top to bottom, and the full-text exclusions each carry a specific reason. You can replicate any of the examples below in our free PRISMA 2020 flow diagram generator by entering your own counts, and this guide walks through worked examples for several review types so you can see how the figure adapts.
The value of an example is that it makes the abstract rules concrete. Reading that "the numbers must reconcile" is one thing; watching 2,244 records become 21 included studies through a clean chain of subtractions is what makes the pattern stick.
How to Read a Completed Flow Diagram
Before the examples, fix the reading order. A reviewer scans a PRISMA flow diagram top to bottom and checks that every number is accounted for at each step. The four phases run in sequence: identification of records, screening of titles and abstracts, eligibility assessment of full texts, and inclusion of the final studies. Between each phase, what leaves one box must arrive in the next minus a documented removal.
The only count permitted to change without a subtraction is the studies-versus-reports distinction at the very bottom, because one study can be described across several reports. Everywhere else, a number that does not subtract cleanly is an error. If those units are unfamiliar, our explainer on what goes in each PRISMA box defines records, reports, and studies precisely.
Example 1: A Standard Database-Only Review
Consider a review that searched three databases. The completed figure below is the kind of annotated, filled-in example you can map straight onto your own review.
Reading it box by box:
- Identification: 1,043 records from PubMed, 712 from Embase, and 489 from Scopus, for 2,244 records identified.
- Records removed before screening: 588 duplicates removed, leaving 1,656.
- Screening: 1,656 records screened, 1,498 excluded at title and abstract.
- Retrieval: 158 reports sought, 11 not retrieved, leaving 147.
- Eligibility: 147 reports assessed; 121 excluded, grouped as wrong population (52), wrong intervention (39), wrong outcome (18), and wrong study design (12).
- Inclusion: 26 reports describing 21 studies included.
Every link reconciles: 2,244 minus 588 is 1,656; 1,656 minus 1,498 is 158; 158 minus 11 is 147; 147 minus 121 is 26; and the 26 reports map to 21 studies because five studies are each reported across two publications. This is the clean chain a peer reviewer checks first.
Example 2: A Review With Other Sources
When a review also searches trial registries, reference lists, or grey literature, the figure uses the layout with a second other sources column. The database path runs as in Example 1, while a parallel column tracks the other-methods records. The figure below shows 45 records from citation searching and registers, of which 6 reach full-text assessment and 2 are included, bringing the combined total to 23. The two columns merge at the inclusion stage so the final count covers both routes. Choosing this layout is a methodology decision, and our overview of the PRISMA 2020 flow diagram templates explains exactly when the other-sources column belongs in your figure.
Example 3: An Updated Review
A review updating a previous version uses the template that keeps the earlier results visible. The diagram shows the studies carried over from the prior review alongside the records newly identified since the last search, and the inclusion boxes report the combined total. This is common in living systematic reviews and Cochrane updates, where each refresh adds to an existing evidence base rather than starting fresh. In the figure below, a fresh search adds 8 new studies to the 15 carried over, for a total of 23 included in the updated review.
Example 4: An Empty Review
An example need not end in a large number. A review that finds no eligible studies fills every box normally and ends with an included count of zero, as the figure below shows.
Here 24 full texts were assessed and all were excluded: wrong population (9), wrong intervention (7), wrong comparator (4), and wrong study design (4). The exclusion reasons sum to 24, the included box reads 0, and the figure proves a genuine evidence gap. Our guide to the empty-review flow diagram covers this case in full.
What Every Good Example Has in Common
Across all four, the same qualities recur. Each database is counted separately in identification. Duplicates are removed in their own box before any human screens a title. Exclusion reasons appear only at the full-text stage and sum exactly to the total excluded. And the studies-versus-reports distinction is respected at the bottom. Reproducing those qualities is what separates a publishable figure from one that draws reviewer queries. When you are ready to build yours, our step-by-step guide to creating a PRISMA flow diagram walks through entering each count, and a quick scan of the most common diagram mistakes catches the errors these examples are designed to avoid.
Frequently Asked Questions
What does a completed PRISMA flow diagram look like?
It shows four phases stacked vertically, with real numbers in each box: records identified per database, duplicates removed, records screened and excluded, reports sought and assessed, full-text exclusions with reasons, and the final included studies. Every count reconciles with the next from top to bottom.
Where can I find a PRISMA flow diagram example to copy?
The worked examples in this guide cover a standard database review, a review with other sources, an updated review, and an empty review. You can reproduce any of them by entering the same counts into a flow diagram generator and exporting the figure.
Do the example numbers have to add up exactly?
Yes. Records identified minus duplicates equals records screened, and so on down to inclusion. The only intentional difference is at the bottom, where the number of reports can exceed the number of included studies because one study may have several publications.
Is there a PRISMA example for a review with no included studies?
Yes. An empty review fills every box as usual and ends with an included count of zero, with the full-text exclusion reasons summing to the total assessed. A well-documented empty review is a legitimate, publishable result that maps an evidence gap.
How many exclusion reasons should an example show?
Enough specific categories to account for every excluded full text, commonly three to seven. In the examples here the reasons such as wrong population, intervention, outcome, and study design each carry a count, and those counts sum exactly to the total excluded at the eligibility stage.