PRISMA Flow Diagram Example and Creation Guide

A PRISMA flow diagram is the chart that shows up near the start of a systematic review's results section, and it's basically the visual story of how a study pool went from thousands of database hits down to the small handful of studies that actually got analyzed. This PRISMA Flow Diagram Example lays out how the flow of information moves through each phase of a systematic review, tracking how many records were found, how many made it through to inclusion, and how many got excluded along the way, together with the reasons behind each exclusion. Below is a worked example using realistic numbers, followed by a plain-language guide you can use to build your own.

What Does a PRISMA Flow Diagram Example Look Like?

A PRISMA flow diagram example usually kicks off with anywhere from a few hundred to several thousand records pulled together through database searching. From there, duplicates get removed, the remaining records are screened by title and abstract, and whatever survives that round gets checked as full text against the eligibility criteria.

What's left at the end is a much smaller set of included studies, often less than 5% of where things started. Every box in the diagram holds a count, and every arrow represents a filtering decision that moves the pool from one stage to the next.

Key Takeaways

A PRISMA diagram has four core phases: identification, screening, eligibility, and included.
The template depends on the review type, whether it's new or an update, and whether it searches databases and registers only or other sources too.
Every excluded record needs a clear reason once you reach full-text screening — vague labels like "not relevant" are a common weak spot.
Cochrane's handbook includes a worked example so reviewers can see a properly completed diagram, and university guides like UNC Chapel Hill's walk through each box.
Free tools, including a Shiny web app and downloadable Word templates, can generate a compliant diagram without design software.

What Does a PRISMA Flow Diagram Actually Show?

A PRISMA flow diagram is basically a picture that traces how information flows through a systematic review or meta-analysis, built around the PRISMA reporting guidelines, which exist to make this kind of research more transparent and easier to trust. It gives readers a visual snapshot of the identification, screening, eligibility, and inclusion stages, so anyone going through the final paper can see for themselves how the study selection actually happened, rather than just taking the authors' word for it.

Think of it as an audit trail. If a reader wants to know whether a review might have missed important studies, or dropped studies for shaky reasons, the flow diagram is where they'd go to check.

What Are the Four Phases of a PRISMA Flow Diagram?

Here's an illustrative example with realistic numbers, not a real published review, just something to show how the counts relate to one another and match the diagram above.

Phase	What happens	Example count
Identification	Records found across all databases searched, before removing duplicates	1,842 records
Duplicates removed	Records removed as duplicates before screening	1,842 → 1,340 records
Screening	Titles/abstracts screened against inclusion criteria	1,340 screened → 1,180 excluded
Eligibility	Full texts assessed for eligibility	160 assessed → 128 excluded, with reasons
Included	Studies included in the final review	32 studies

Reading this table the way a reviewer would: nearly 1,850 records shrank down to 32 studies, a survival rate of roughly 1.7%. That drop looks dramatic, but it's actually normal for this kind of review. Many reviewers also break down how many results came from each individual database, for example noting that Medline contributed 135 records while CINAHL Plus contributed another chunk. This helps readers see where most of the initial pool came from.

At the eligibility stage, reviewers list the specific reason behind each excluded full text. Common categories include wrong setting, wrong patient population, wrong intervention, or wrong outcome. Each excluded report should only be counted once, even if it technically meets more than one exclusion reason.

Should You Use the Databases-Only or Databases-Plus-Other-Sources Layout?

The official PRISMA 2020 templates come in a few different versions: one for new reviews that searched only databases and registers, another for new reviews that also pulled in other sources like citations or grey literature, and separate versions built for updated reviews.

So which one fits your project? If your search strategy included hand-searching reference lists, reaching out to authors directly, or checking trial registries, you'll want the "other sources" layout. It adds a second column that runs alongside the database column, then merges back together with it at the included-studies box.

Getting this choice wrong is actually one of the most common formatting mistakes reviewers run into when submitting for publication, so it's worth double-checking before you commit to a layout.

Why Do PRISMA Numbers Shrink So Much at Each Stage?

That steep drop-off isn't a design flaw. It's actually a natural result of how systematic search is supposed to work.

Database searches are built to be broad on purpose. They use lots of synonyms and subject headings to make sure nothing important gets missed, which means the identification stage almost always pulls in far more records than will end up being relevant. Screening then trims away the records that are obviously off-topic just from reading the title or abstract.

Full-text eligibility review is the strictest filter of all, and for good reason — it's the only stage where reviewers can actually dig into methodology, population, and outcomes and check them properly against the review's inclusion criteria.

So a tight final list isn't a sign of weakness. If anything, a diagram with almost no exclusions at any stage is usually a red flag that the search was too narrow from the start.

What Mistakes Should You Avoid When Building One?

Reporting one combined exclusion number without giving reasons at the full-text stage
Double-counting a report that was excluded for more than one reason
Mixing 2009-format boxes with 2020-format wording in the same diagram
Forgetting to note how many records came from each individual database
Leaving out the "duplicates removed" step, which makes the identification count misleading

What Free Tools Can Generate a PRISMA Flow Diagram?

The PRISMA statement site offers downloadable Word templates for each diagram type, and you can also generate flow diagrams using a companion Shiny web app. Diagram tools like Creately offer an editable flowchart version too, which exports to JPEG, PNG, or SVG for direct use in Word, PowerPoint, or Excel.

Whichever tool you end up using, just make sure the box wording stays consistent with the official template, so reviewers and journal editors recognize the format right away.

Where Do AI Tools Fit Into the Process?

The identification and screening phases are where most of a reviewer's time actually goes, reading through titles and abstracts for hundreds or even thousands of records. AI-assisted research tools can speed up that early triage by summarizing abstracts, surfacing a paper's stated population and methods, and helping a reviewer decide faster whether a record is worth a full-text read.

That said, these tools don't replace the eligibility assessment itself, and a PRISMA diagram should still reflect inclusion criteria applied by a human. What AI can offer is faster, clearer summaries at the identification and screening stages, which means fewer hours spent before you even get to the numbers that end up in your diagram.

Frequently Asked Questions

What is a PRISMA flow diagram used for?

It lays out the path a review's authors followed, from that first search all the way to the final list of studies, so readers can judge for themselves whether the work held up.

How many phases does a PRISMA flow diagram have?

Four: identification, screening, eligibility, and included. Identification means pulling records from databases and reference lists. Screening is checking titles and abstracts. Eligibility is the full-text check. Included is what's left standing after all that.

Is PRISMA only for medical research?

Not anymore. It began in health research, but the same approach to clear, structured reporting has caught on in other fields that run systematic reviews.

What's the difference between the 2009 and 2020 PRISMA flow diagrams?

The 2020 version is more detailed and covers reviews that search registers plus other non-database sources. Diagrams still built on the old 2009 boxes should be updated before a new submission.

Do I need to list a reason for every excluded record?

Only at the full-text stage. Screening exclusions get grouped into one number, but each full-text exclusion needs its own stated reason.

Can I generate a PRISMA diagram automatically?

Yes. There's a free Shiny app tied to the official PRISMA 2020 statement where you just plug in your counts, plus a few other tools that offer ready-made templates.

Next Step

If you're currently working through the identification or screening stage of a review, Canyam can help you get through abstracts faster with AI-generated summaries built specifically for academic papers. You can search across more than 65 million papers, pull out the key findings in minutes, and save your full-text reading time for the studies most likely to actually land in your PRISMA Flow Diagram Example. Try Canyam's paper search and summaries to speed through the stage that happens well before your PRISMA counts even begin.