How do I make a CONSORT diagram and complete the CONSORT 2025 checklist for my trial?

What is a CONSORT diagram?

CONSORT (Consolidated Standards of Reporting Trials) is the reporting guideline for randomized controlled trials. It has two parts: a checklist of what the paper must report, and a flow diagram that shows how participants moved through the trial. The diagram answers the question every reader and reviewer asks first: of the people you screened, how many were randomized, how many received what they were allocated, how many you lost, and how many ended up in the analysis of the primary outcome.

Checklist item 22a in CONSORT 2025 asks for participant flow for each group, and names the flow diagram as the way to show it. Journals that endorse CONSORT expect to see the diagram in the paper, usually as the first figure.

What changed in CONSORT 2025 compared with CONSORT 2010?

CONSORT 2025 was published on 14 April 2025, simultaneously in the BMJ, JAMA, The Lancet, Nature Medicine and PLOS Medicine, led by Sally Hopewell and colleagues, with a separate explanation and elaboration paper in the BMJ. It replaces CONSORT 2010, which had 25 items.

The wording was also harmonised with SPIRIT 2025, the companion guideline for trial protocols, so a protocol written to SPIRIT maps more cleanly onto a results paper written to CONSORT.

What does the CONSORT checklist contain?

The 2025 checklist is organised into six sections. Here is what each group asks for, in our own words; use the official editable checklist from consort-spirit.org for submission.

The checklist is written around the two-group parallel trial, but the authors state it applies to all randomized trials; for other designs you add the relevant extension (below).

Is the CONSORT diagram only for RCTs?

The CONSORT flow diagram was built for randomized trials, and its allocation stage only makes sense when there is randomization. Observational studies have their own guideline, the STROBE checklist for observational studies, which also recommends considering a flow diagram of participants. Many cohort papers use a CONSORT-style chart for that, which is fine, but label it a participant flow diagram rather than a CONSORT diagram. If you are unsure which guideline governs your design, start with which reporting guideline your study needs.

How do I fill in the CONSORT flow diagram? A worked example

The official 2025 template has four labelled stages. The example below uses synthetic data for an invented two-arm trial; it is illustrative only.

1. Enrolment. Assessed for eligibility: n = 412. Excluded: n = 112 (did not meet inclusion criteria, n = 71; declined to participate, n = 33; other reasons, n = 8). Randomized: n = 300.
2. Allocation. Intervention arm: allocated n = 150; received the allocated intervention n = 146; did not receive it n = 4 (withdrew consent before first dose, n = 3; became ineligible, n = 1). Control arm: allocated n = 150; received n = 149; did not receive n = 1 (withdrew consent, n = 1).
3. Follow-up. Intervention arm: lost to follow-up for the primary outcome n = 9 (moved away, n = 5; unreachable, n = 4); discontinued the intervention n = 6 (adverse event, n = 4; patient choice, n = 2). Control arm: lost to follow-up for the primary outcome n = 11; discontinued the intervention n = 4.
4. Analysis. Intervention arm: analysed for the primary outcome n = 141; excluded from analysis n = 0. Control arm: analysed n = 139; excluded n = 0.

Now check the arithmetic, because reviewers will:

Two points the example illustrates. First, the six participants who discontinued the intervention are still analysed in their randomized group, because their outcome was measured; discontinuing treatment is not the same as being lost to follow-up. Second, 412 minus 112 must equal 300; a diagram in which boxes do not add up is one of the most common reasons for a revision request. The numbers in the diagram must also match the abstract, the baseline table and the denominators in the results tables.

How do I make a CONSORT diagram in Word or another tool?

1. Start from the official template. consort-spirit.org provides the CONSORT 2025 flow diagram as an editable Word file. Using it keeps the 2025 box wording (for example, losses and analyses defined for the primary outcome).
2. Collect the counts from your screening log and database, not from memory. You need the screening log for enrolment and exclusions, the randomization list for allocation, and the analysis dataset for the final boxes.
3. Adapt the structure to your design. Add columns for extra arms in a multi-arm trial; for a cluster trial, report clusters and individuals at each stage, as the cluster extension recommends; for pilot trials, the pilot and feasibility extension has its own diagram.
4. Build it in the tool you will keep editing. Word or PowerPoint shapes are fine for most journals. In R, the CRAN package consort generates diagrams from a participant-level dataset, which avoids transcription errors when numbers change.
5. Export in the format and resolution your target journal's figure instructions require, and cite the figure in the results text.
6. Reconcile every number against the text, abstract and tables before submission.

CliniPaper can recompute the flow diagram totals and cross-check them against your abstract, tables and results text, flagging any box that does not add up. You remain responsible for the final figures, and if you use an AI tool in preparing the manuscript, disclose it as your target journal requires; see our guide to the AI disclosure statement for medical journals.

Which CONSORT extensions might apply to my trial?

The consort-spirit.org extensions page lists more than 20 extensions. As of October 2026, nearly all are still based on CONSORT 2010; the children and adolescents extension (CONSORT-C) is the one listed as built on CONSORT 2025. Use the main checklist plus every extension that fits your design.

Common mistakes reviewers flag

• Numbers that do not add up between boxes, or that differ from the abstract and tables.
• Missing reasons. Every exclusion, loss and discontinuation box needs reasons, not just counts.
• Treating discontinuation as loss to follow-up, which inflates missing data and misdescribes the analysis population.
• No statement of the analysis population (item 21b) or of how missing data were handled (item 21c), both new emphases in 2025.
• Old template or old checklist. Submitting the CONSORT 2010 checklist in 2026 signals the paper was not checked against the current standard.
• Missing open science items: registry number, protocol and analysis plan access, data sharing statement and conflicts of interest.
• Cluster trials reported only at the individual level, without cluster counts at each stage.

When the reviewers do flag these, our guide on how to respond to reviewer comments shows how to answer point by point.