CONSORT Checklist

What CONSORT is

CONSORT sets out the minimum a report of a randomized controlled trial must contain so that readers can judge how the trial was run and how far to trust its results. The current version, CONSORT 2025, replaced CONSORT 2010 and has a 30-item checklist plus a participant flow diagram. It adds a dedicated open science section covering trial registration, the protocol, the statistical analysis plan, data sharing and conflicts of interest.

Most clinical journals require CONSORT for any randomized trial, and many ask you to upload the completed checklist with page numbers at submission. Editors often screen for it before a manuscript reaches peer review.

When it applies

Use CONSORT for randomized controlled trials of any intervention. Extensions exist for specific designs, including cluster, non-inferiority and equivalence, crossover and pilot trials, and for trial abstracts. A trial protocol is reported with SPIRIT, not CONSORT.

What the checklist covers

• Title and abstract: identified as randomized in the title; a structured summary of design, methods, results and conclusions.
• Open science: registry name and number, where the protocol and statistical analysis plan can be found, data sharing, funding and conflicts of interest.
• Introduction: background, rationale and specific objectives.
• Methods: trial design, participants and settings, interventions in enough detail to replicate, prespecified outcomes, sample size calculation, how the random sequence was generated and concealed, who was blinded, and the statistical methods.
• Results: participant flow with numbers at each stage (the CONSORT diagram), recruitment dates, baseline characteristics, outcomes with effect sizes and precision, and harms.
• Discussion: interpretation, limitations and generalisability.

What authors most often miss

• Allocation concealment described only as "randomized", with no account of how the sequence was hidden from those enrolling participants.
• A sample size calculation without the assumed effect size, variability, power and alpha.
• Outcomes changed after the trial started without saying so, or outcomes in the paper that differ from the registry entry.
• A flow diagram with numbers that do not reconcile with the results tables.
• Harms reported vaguely or not at all.

Ophthalmology: one eye or two?

Ophthalmology trials often enrol both eyes of a patient, or randomize one eye to each arm. CONSORT asks you to state the unit of randomization and analysis. If you include both eyes, say how you accounted for the correlation between fellow eyes (for example with generalized estimating equations or mixed models). Reviewers frequently return manuscripts that treat two eyes of one patient as independent observations.