CONSORT at 30 years: history, evolution, and impact of a reporting guideline for randomized controlled trials - Part 1.

Abstract

The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed to improve the transparency and completeness of reporting randomized controlled trials (RCTs). Since its first publication in 1996, CONSORT has become the international standard for reporting RCTs and has influenced the development of reporting guidelines across health research. This article describes the history, evolution, and impact of CONSORT from its beginnings in the early 1990s to the publication of CONSORT 2025. It draws on published reports, historical records and contributions from original developers and current members of the CONSORT and SPIRIT Executive group. Concerns regarding the poor reporting of RCTs, and the limitations this imposed for critical appraisal, systematic reviews and their ability to inform clinical practice guidelines, motivated the development of structured reporting guidance. Independent initiatives by the SORT Group in Ottawa and the Asilomar Working Group led to the production of the original CONSORT Statement in 1996, which introduced a checklist and participant flow diagram for reporting RCTs. Subsequent updates in 2001, 2010, and 2025 refined and expanded the guidance in response to emerging methodological evidence and user feedback. CONSORT also stimulated the creation of extensions addressing specific trial designs, interventions, and reporting issues, as well as related initiatives including SPIRIT, QUOROM, STARD, and the EQUATOR Network. Over three decades, CONSORT has become the international standard for reporting RCTs, endorsed by leading journals and editorial organizations worldwide. Evidence suggests that journal endorsement of CONSORT improves reporting completeness, although adherence remains inconsistent. Continued innovation, harmonization with related initiatives, and improved implementation strategies are still required to ensure transparent, reproducible, and trustworthy reporting of RCTs in the future. Randomized controlled trials are important studies that help determine whether health treatments and other interventions work. However, if trial reports leave out key details about what researchers did and what they found, clinicians, patients, policy-makers, and other researchers cannot judge the results properly or use them confidently. This article describes the 30-year history of the CONSORT Statement, an international guideline designed to help researchers report randomized trials clearly and completely. CONSORT began in the mid-1990s, when two groups of researchers and journal editors independently developed proposals to improve poor reporting of trials. They combined their work, publishing the first CONSORT Statement in 1996. It included a checklist and a participant flow diagram to show how people moved through a trial. CONSORT has been updated several times as research methods and reporting needs have changed, most recently in 2025. The newest version gives greater attention to issues such as open science, data sharing, trial registration, and involving patients and the public. CONSORT has also led to related guidance for types of trials and has influenced reporting guidance for many other kinds of health research. Evidence indicates that trials published in journals that endorse CONSORT tend to report more essential information. Nevertheless, use of the guideline remains inconsistent. Researchers, journal editors, peer reviewers, and funders all have a role in making complete and transparent reporting routine. Better reporting makes trial findings easier to assess, reproduce, combine in systematic reviews, and use to improve health care.