Availability of clinical trial individual patient data in the BMJ before and after adoption of a stringent data-sharing policy, compared with recent rates at other major medical journals

Abstract Background In 2024, the BMJ updated its data-sharing policy for clinical trials, requiring open deposit of deidentified individual participant data (IPD) before publication. We considered whether data-sharing increased after introduction of the new policy, and compared rates of data-sharing in 2025 with those of other leading medical journals. Method All data-sharing statements were downloaded from BMJ trials published in 2023 (submitted pre-updated policy) and 2025 (submitted post-updated policy). Data for 2025 were gathered for trials in five comparison medical journals that had less stringent data-sharing requirements. Data-sharing statements were coded to specify whether IPD were immediately available, and if not, why. We did not check quality of IPD or reproducibility of results. Results Openly available IPD for BMJ trials increased from 0/32 in 2023 to 19/33 (58%) after the updated policy; seven articles gave repository links that did not yield any data. In comparison journals, most authors provided data-sharing statements, but rates of open IPD varied from 0% to 5.6%. Conclusions There was a substantial increase in open sharing of IPD after introduction of the new BMJ policy compared to a prior period, and compared to other journals in 2025.