Secondary use and scholarly impact of a portfolio of clinical trials with shared individual participant level data:...

To assess the number, timing, characteristics, and scholarly impact of secondary publications generated using individual participant level data (IPD) from a portfolio of clinical trials shared with external investigators through a data sharing platform.

Cross sectional study.

Yale University Open Data Access (YODA) Project platform.

Johnson & Johnson sponsored clinical trials listed on the YODA Project platform with IPD available for external sharing through 2021 and with a full length, peer reviewed publication (that is, primary publication) reporting primary endpoint results by the original trial investigators.

Number, timing, research objectives, analysis type, and scholarly impact of secondary publications using IPD from these trials identified through Web of Science citation searches of primary publications through June 2025. Scholarly impact metrics included journal impact factor, annual citation count, and annual Altmetric Attention Score. Secondary publications were classified as internal (authored by at least one original trial investigator) or external.

Among 336 eligible trials, 265 (79%) had at least one associated secondary publication, totalling 1167 publications, of which 209 (17.9%) were external. Among external publications with a reported data access mechanism (n=190; 91%), most obtained access through data sharing platforms (n=161; 85%), primarily the YODA Project (n=157; 83%). Over time, the proportion of external publications increased steadily, exceeding 50% of all secondary publications by year 11 and thereafter. Compared with internal publications, external publications were more frequently pooled analyses (151/209 (72%) v 534/958 (55.7%); P<0.001) and involved predictive or prognostic modelling (108/209 (51.7%) v 322/958 (33.6%); P<0.001), development of statistical models or algorithms (60/209 (29%) v 114/958 (11.9%); P<0.001), and validation of existing methods, models, or risk scores (32/209 (15%) v 66/958 (6.9%); P<0.001). Compared with internal publications, external publications were published in journals with higher impact factors (median 6.7 (interquartile range 3.4-16.6) v 4.6 (2.9-10.2); P=0.002) and had higher annual Altmetric Attention Scores (median 2.1 (0.7-7.1) v 0.6 (0.3-2.3); P<0.001) but had lower annual citation counts (median 2.7 (1.1-5.6) v 3.4 (1.6-7.5); P<0.001) and were less likely to be cited in clinical guidelines (21/184 (11%) v 235/805 (29.2%); P<0.001) or policy documents (14/184 (8%) v 206/805 (25.6%); P<0.001).

Most trials in this portfolio of clinical trials, for which IPD were available through a data sharing platform, generated secondary research by both original trial investigators and external investigators. External investigators most often accessed data through the data sharing platform, and their publications accounted for an increasingly larger proportion of secondary publications over time. These findings suggest that structured data sharing mechanisms may support additional secondary use of clinical trial data and further enhance the scientific value of clinical trials.