This #TalkClinicalTrials blog is by Drs. David Moher and An-Wen Chan who are both Ontario-based researchers. Dr. Moher is a clinical epidemiologist at the University of Ottawa and Ottawa Hospital Research Institute, and Dr. Chan is a clinical epidemiologist and dermatologist at the University of Toronto and Women’s College Research Institute.
Drs. Moher and Chan are on the CONSORT Executive Committee. CONSORT stands for the Consolidated Standards of Reporting Trials – a set of guidelines for reporting randomized controlled trials. The CONSORT statement was recently updated, and who better to answer a few questions about it than Drs. Moher and Chan?
About CONSORT, the history, and why it’s important
The history of CONSORT and what it is
During the 1980s, the prevalence of poor reporting in randomized controlled trials (RCTs) became increasingly evident as systematic reviews gained prominence. These reviews systematically evaluated the quality of included trials and consistently revealed how RCTs were poorly reported.
By 1993, the inadequacy of RCT reporting had reached a point that prompted a meeting of assessment tool developers to create a new assessment instrument for RCTs. However, upon further examination, we realized that the fundamental issue was more basic: the reporting quality of published RCTs was so inadequate that meaningful assessment was virtually impossible. The group shifted its approach and redirected efforts toward improving the actual reporting standards for RCTs. The outcome was the Standards of Reporting Trials (SORT) guideline, published in 1994.
At the same time, another independent initiative was underway. The Asilomar group, with objectives similar to SORT, had also developed recommendations for improving RCT reporting. The two groups met and agreed to create one reporting guideline, which resulted in CONSORT in 1996.
Why CONSORT is important
Prior to CONSORT no global standard existed for reporting RCTs. CONSORT was an opportunity for authors anywhere in the world to use a standard, minimum guidance to report their RCTs.
One unique feature of CONSORT is its use of evidence, whenever possible. For example, CONSORT asks authors to report on several aspects of randomization. Authors are asked to report this information because evidence indicates that inadequate allocation concealment (a part of the randomization process) can lead to biased results. Another reason CONSORT is important is the evidence that using CONSORT versus not using CONSORT improves the quality of reporting published RCTs.
The update to CONSORT and what’s new
How this version of CONSORT was created
A scoping review of the literature was the starting point for the CONSORT update, along with a database of evidence related to CONSORT that we developed. From this work, and recommendations from authors of CONSORT extensions, other reporting guidelines, and personal communications with other experts, we created a list of potential changes for the updated CONSORT checklist. This list of potential changes to the checklist was then assessed in a large, international, online, three-round Delphi survey (317 participants) and discussed at a two-day virtual expert consensus meeting (30 invited international participants).
What is new to CONSORT and updates
We added 7 new items related to transparency, patient engagement (also called patient and public involvement or PPI for short), and methods, and integrated key items from core CONSORT extensions. We also added a new Open Science section that grouped together items relevant to transparency. Given their close relationship, we aligned the wording of the checklist with relevant SPIRIT 2025 protocol items.
How to implement this version of CONSORT
Why people should use CONSORT
CONSORT provides a standard template to report randomized trials. Hundreds of journals have explicitly endorsed CONSORT as a reporting standard for authors to use when submitting reports of completed randomized trials. This harmonization makes knowing what to report more efficient for authors. There is evidence that using CONSORT (versus not using CONSORT) improves the quality of reporting randomized trials.
How people implement/use CONSORT
Authors refer to the CONSORT checklist (currently 30 items in the 2025 update) and the participant flow diagram when preparing manuscripts. Each checklist item addresses a specific aspect of trial reporting, including trial design, participant flow, statistical methods, outcomes, interpretation, and funding sources. The Explanation and Elaboration paper (BMJ 2025) also serves as an important learning resource by providing detailed explanations and model examples.
A bit of other information about CONSORT
CONSORT is considered the first ‘modern’ reporting guideline. The approach to developing CONSORT has been used to create hundreds of other reporting guidelines, such as PRISMA (for reporting systematic reviews) and STARD (for reporting diagnostic test accuracy studies). SPIRIT, a reporting guideline for protocols of randomized trials, is closely aligned with CONSORT. CONSORT was also key in the development of the EQUATOR Network (Enhancing the Quality and Transparency Of health Research).