What it shows
The participant flow diagram from the CONSORT 2010 Statement, redrawn as a vector. It follows participants through a two-group parallel randomized trial in four stages: enrollment, allocation, follow-up and analysis.
It keeps the template’s wording, UK spellings included, and both arms read “Allocated to intervention” because the template does not name them; in a controlled trial one arm is the comparator. Every count is left blank.
How to read it
At the top, those assessed for eligibility minus those excluded give the number randomized.
The diagram then splits into the two arms, each recording who received the allocated intervention and who did not.
Follow-up records those lost to follow-up or who discontinued the intervention. The final row records who was included in the analysis and who was excluded from it.
Each exclusion box asks for reasons, so a reader can see where and why participants left the trial.
What each box records
- Enrollment: assessed for eligibility; excluded (not meeting inclusion criteria, declined to participate, other reasons); randomized.
- Allocation, each arm: allocated to intervention; received it; did not receive it (give reasons).
- Follow-up, each arm: lost to follow-up (give reasons); discontinued intervention (give reasons).
- Analysis, each arm: the number analyzed; excluded from analysis (give reasons).
- This is the 2010 version. In CONSORT 2025, follow-up lists discontinued intervention first and counts those lost to follow-up for the primary outcome, and the analysis box counts those analyzed for the primary outcome.
Ways to use it in teaching
Give students a short published trial report and have them fill in the counts from its methods and results sections.
In an evidence-based practice module, it shows how attrition is reported.
Comparing it with the CONSORT 2025 version shows that reporting standards change; a journal’s instructions usually say which version it expects.
For studies that cannot randomize, see our guide to quasi-experimental design.
Sources
Schulz, K. F., Altman, D. G. and Moher, D., for the CONSORT Group (2010), "CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials", BMJ 340: c332, Figure 1, doi:10.1136/bmj.c332; the CONSORT Group's "CONSORT 2010 Flow Diagram" template (consort-statement.org). Hopewell, S. et al. (2025), "CONSORT 2025 statement: updated guideline for reporting randomised trials", BMJ 389: e081123, doi:10.1136/bmj-2024-081123.
