The Epistemonikos Database of Trials: A Comprehensive and Freely Accessible Bibliographic Source of Randomized Trials in Health

Abstract Randomized controlled trials (RCTs) are the cornerstone of evidence-based healthcare, providing the most reliable means of assessing the efficacy and safety of health interventions. However, their rapidly growing volume and dispersion across diverse sources, such as bibliographic databases, preprint servers, and trial registries, pose major challenges for evidence synthesis, clinical guideline development, and health technology assessment. Despite longstanding recognition of their importance and multiple initiatives to improve accessibility, there is still no comprehensive, freely available, and continuously updated resource of trial records. To address this gap, the Epistemonikos Foundation developed the Epistemonikos Database of Trials (ED-Trials), a continuously updated repository of RCTs identified from more than 30 sources, including bibliographic databases, preprint servers, international trial registries, and other search sources. This paper describes the methods used to identify and classify trial records, outlines the key features of the search interface, and reports the database status as of October 2025. ED-Trials now includes more than 1.5 million unique trial records, many of which are not indexed in MEDLINE or other conventional bibliographic databases. It represents a significant scholarly and technical achievement, offering a freely accessible and user-friendly resource that enables more efficient, comprehensive, and up-to-date identification of randomized controlled trials, thereby strengthening the foundation of evidence-based healthcare. Competing Interest Statement Epistemonikos Database of Trials was developed and is maintained by Epistemonikos Foundation, a non-profit organisation with a strict policy to avoid financial conflict of interests. Details about this policy and financial support can be found on the website of the Foundation (https://foundation.epistemonikos.org/). All authors, as developers of the database, have some degree of academic conflict of interests with this article. Funding Statement The salary of all the authors is totally or partially paid by Epistemonikos Foundation. The authors received no additional financial support for the research, authorship, and/or publication of this article. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the present study are available upon reasonable request to the authors Data Availability All data produced in the present study are available upon reasonable request to the authors