CONSORT 2025: an overview for trial authors
A randomized trial report needs to let readers follow the study from its original question to the people included in each analysis. CONSORT 2025 provides a reporting framework for that task. This overview is for authors preparing a trial manuscript, not a substitute for the full guideline or for advice about trial design. Use it to organize the report and identify details to retrieve from the trial records.
Why it matters
The CONSORT 2025 statement presents updated guidance for reporting randomized trials [1]. Its companion explanation and elaboration provides context and examples for interpreting the guidance [2]. Clear reporting lets readers locate the methods, follow what happened to participants and distinguish planned work from later decisions. It does not establish that the methods were appropriate or that the findings are dependable.
Treat a reporting checklist as a map to the manuscript, not a certificate. A report can describe a method completely and still leave a substantive concern for readers or reviewers. Conversely, an absent detail may be a reporting omission rather than evidence that a procedure never happened. Authors should describe what actually occurred, including departures from the plan, instead of filling gaps with what they wish had occurred.
Key ideas
Choose the right document and scope
CONSORT concerns the trial report. SPIRIT 2025 concerns randomized-trial protocols [3]. Keep the two documents connected, but do not use a protocol checklist as if it covers the results paper. Identify whether a design-specific extension also applies, such as one for cluster trials, pilot trials or non-inferiority trials. Check compatibility and version differences before copying item numbers from an older checklist.
Keep the plan visible
Locate the registry record, dated protocol and statistical analysis plan before drafting. Report where readers can find the relevant documents and explain meaningful changes to outcomes or analyses. A final report should not silently rewrite the original question to match the results. If a document is unavailable, describe the limitation honestly rather than supplying a link that does not contain it.
Explain the comparison and allocation
Name the trial design, eligibility criteria, setting, interventions and comparator. Explain how the random sequence was generated, how upcoming allocations were concealed and who carried out the relevant steps. These are separate questions. A report that simply says participants were randomly assigned leaves the reader without the practical details needed to understand the process.
Describe who knew the assignments and when. Do not use a broad masking label in place of naming participants, clinicians, outcome assessors or analysts as appropriate. Give enough detail about the comparator for a reader to understand the actual contrast, rather than relying on the phrase usual care alone.
Track people and denominators
Reconcile the numbers screened, randomized, followed and analyzed for each group. Reasons for exclusions or missing observations belong with the relevant stage. Distinguish stopping the intervention from leaving follow-up: the two need not mean the same thing. The flow account, outcome tables and abstract should not tell different stories about the number of participants contributing data.
A denominator is specific to an outcome and analysis. Do not assume that one final number describes every table. If different outcomes have different amounts of missing data, make those differences visible and explain how the analyses handled them.
Report outcomes and harms together
Define outcomes and assessment times clearly, then present group results and the comparison with its uncertainty. Distinguish primary from secondary outcomes and planned from exploratory analyses. Report harms with enough detail to understand how they were collected and which people contributed observations. An absence of recorded harms is not the same as evidence that no harm was possible.
Finish the transparency record
Check the guideline for information on funding, competing interests, data sharing and patient or public involvement [1,2]. Describe actual arrangements rather than aspirational promises. If access requires an application or has restrictions, say so. Keep the discussion proportionate to the design, uncertainty and limitations instead of treating a favorable result as the only feature worth explaining.
Worked example
Illustrative example (invented). Not a real study.
An invented team reports a randomized trial of appointment reminders versus a printed appointment card. The example illustrates reporting decisions only; it supplies no treatment-effect estimate.
- Identify the design. The title and abstract say this is a randomized trial. The methods describe how allocation was generated and concealed.
- Reconcile flow. Of 150 people screened, 30 were not randomized. The remaining 120 were allocated equally: 60 to reminders and 60 to the card.
- Separate missing outcomes. The primary outcome was available for 58 reminder participants and 57 card participants. The report explains the two and three missing observations and the analysis method used for missing data; it does not simply rename these groups as the whole trial.
- Connect to the plan. The author checks the outcome definition and assessment time against the dated protocol and registry record. Any difference is described, with its reason.
- Check consistency. The abstract, flow account and outcome table use matching numbers. The completed checklist points to each location, with a reason where an item does not apply.
No conclusion about benefit follows from these flow counts. They show only who contributed information. A statistical review of the eventual results remains a separate task.
Common pitfalls
- Treating checklist completion as validation. Reporting completeness is not proof of sound design or analysis.
- Confusing concealment and masking. Explain allocation protection and knowledge of assignment separately.
- Dropping people silently. Account for missing outcomes and analysis populations by group.
- Changing the primary outcome without explanation. Keep the original plan and later changes distinguishable.
- Describing the comparator vaguely. Readers need to know what the other group actually received.
- Pasting an old checklist. Confirm the version and any relevant extension before completing it.
Quick self-check, in our own words
- I identified the trial design and checked relevant extensions.
- I can locate the registry, protocol and analysis plan used for the report.
- I described the intervention, comparator and allocation process.
- I explained who knew the assignments.
- My flow counts and outcome denominators reconcile.
- I reported outcome definitions, harms and uncertainty without overstating the findings.
- My checklist points to the final manuscript rather than an earlier draft.
Further reading
- Read the CONSORT 2025 statement [1] alongside its explanation and elaboration [2].
References
- Hopewell S, Chan AW, Collins GS, Hróbjartsson A, Moher D, Schulz KF, et al. CONSORT 2025 statement: updated guideline for reporting randomised trials. BMJ. 2025;389:e081123. doi:10.1136/bmj-2024-081123. PMID: 40228833.
- Hopewell S, Chan AW, Collins GS, Hróbjartsson A, Moher D, Schulz KF, et al. CONSORT 2025 explanation and elaboration: updated guideline for reporting randomised trials. BMJ. 2025;389:e081124. doi:10.1136/bmj-2024-081124. PMID: 40228832.
- Chan AW, Boutron I, Hopewell S, Moher D, Schulz KF, Collins GS, et al. SPIRIT 2025 statement: updated guideline for protocols of randomised trials. BMJ. 2025;389:e081477. doi:10.1136/bmj-2024-081477. PMID: 40294953.