CONSORT (Consolidated Standards of Reporting Trials)

CONSORT stands for Consolidated Standards of Reporting Trials, a reporting guideline designed to improve the transparency and completeness of published reports of randomized controlled trials. The current version, the CONSORT 2025 statement, consists of a 30 item checklist covering the essential information that should appear in a trial report and a flow diagram that tracks participant progress through the phases of enrollment, allocation, follow up, and analysis. First published in 1996 and updated in 2001, 2010 and 2025, CONSORT is endorsed by hundreds of medical journals and by editorial organizations such as the International Committee of Medical Journal Editors, the World Association of Medical Editors and the Council of Science Editors. CONSORT 2025 supersedes the 2010 statement, which its authors say should no longer be used.

Incomplete reporting of clinical trials makes it impossible for readers to assess the validity of findings, replicate studies, or include them in systematic reviews and meta analyses. Before CONSORT, many trial reports omitted critical details such as the method of randomization, allocation concealment procedures, and reasons for participant withdrawal. Studies have shown that adoption of CONSORT by journals is associated with improved reporting quality. For researchers, following CONSORT from the outset, during protocol development rather than at the manuscript stage, helps ensure that essential design elements are planned, documented, and reported.

The CONSORT 2025 checklist covers all major sections of a trial report: title and abstract; a new open science section (trial registration, access to the protocol and statistical analysis plan, data sharing, and funding and conflicts of interest); introduction; methods (including patient and public involvement, trial design, participants, interventions and comparators, outcomes, harms, sample size, randomization, blinding, and statistical methods such as how missing data were handled); results (including participant flow, baseline data, outcomes, and harms); and discussion (interpretation and limitations). Compared with CONSORT 2010, it adds seven new items, revises three, deletes one, and integrates items from the Harms, Outcomes, and Nonpharmacological Treatment extensions. The flow diagram shows the number of participants screened, excluded, randomized to each arm, lost to follow up, and analyzed. Extensions of CONSORT address specific trial designs (such as cluster randomized, crossover, multi arm, noninferiority, and pragmatic trials), interventions (herbal, nonpharmacological, acupuncture), and data types (patient reported outcomes, harms). Most existing extensions were built on earlier versions of CONSORT; until each is aligned with CONSORT 2025, the CONSORT group recommends using the existing version of the relevant extension. Researchers complete the checklist during manuscript preparation and submit it alongside the manuscript.

Use CONSORT whenever you report a randomized controlled trial, regardless of the intervention type, clinical setting, or journal. Many journals require CONSORT checklist submission as a condition of peer review. Even when a journal does not mandate CONSORT, following the checklist improves the quality and completeness of the manuscript. CONSORT is also valuable during protocol development, as the checklist items align with the elements that should be prespecified in a trial protocol. The protocol itself should follow SPIRIT 2025, the companion guideline for trial protocols, which was updated alongside CONSORT 2025 with harmonized wording. Systematic reviewers can use CONSORT to judge how completely included trials are reported, but CONSORT is not a quality assessment instrument: judging a trial's risk of bias requires a dedicated tool such as the Cochrane RoB 2 tool.

A frequent mistake is treating CONSORT as a checklist to complete retroactively rather than as a guide for planning the trial from the start. This often results in missing information because the relevant data were never collected. Another error is filling in the checklist perfunctorily, citing page numbers for items that are only partially reported. Researchers sometimes confuse the CONSORT flow diagram with a statistical analysis diagram, omitting the enrollment and allocation phases. Using an outdated version of the CONSORT checklist (CONSORT 2025 has replaced the 2010 checklist) or failing to use the appropriate extension for your trial design (such as the cluster or crossover extension) is another common oversight.

A research team publishes a three arm randomized trial comparing cognitive behavioral therapy, medication, and their combination for adolescent depression. Their CONSORT flow diagram shows that 450 adolescents were assessed for eligibility, 120 were excluded (80 did not meet criteria, 40 declined), and 330 were randomized equally to three arms. During the 12 month follow up, 28 participants were lost (12 in the therapy arm, 9 in the medication arm, 7 in the combination arm), and reasons for loss are documented. The checklist confirms reporting of the randomization sequence (computer generated), allocation concealment (central phone system), and blinding (assessors blinded to allocation). This level of detail allows readers and reviewers to assess the trial's internal validity.