Clinical Evidence Behind a Paywall: An Analysis of Randomised Clinical Trials Included in Cochrane Reviews

ABSTRACT Open access to health evidence is essential for informed decision‐making, yet many randomised controlled trials (RCTs) remain behind paywalls. This study assessed the accessibility of RCTs cited in Cochrane intervention systematic reviews, focusing on open access availability and alternative access options. We analysed 491 RCTs from a random sample of 50 Cochrane reviews published in early 2023. Overall, 43.0% required payment for access, but this proportion declined over time, from 60.0% for articles published between 1980 and 1999 to 20.7% for those from 2020 to 2023. Among paywalled articles, the lowest fee provided 24‐h access in 37.0% of cases. However, 49.8% of these studies were available in full text via Google Scholar, and 95.3% of the remaining could be accessed through Sci‐Hub. Despite the persistent presence of paywalls, access barriers have decreased over time, and alternative platforms provide widespread availability of restricted articles.