Timely dissemination of clinical trial results is essential to advance knowledge, guide practice, and improve outcomes, yet many trials remain unpublished, limiting impact. We examine what drives publication and timelines across three major clinical domains.

We analyzed study design and factors associated with dissemination of interventional trials, focusing on cardiovascular disease (CVD), cancer, and COVID-19. A total of 10,785 trials (CVD: 5929; cancer: 4210; COVID-19: 646) were linked to PubMed publications using National Clinical Trial identifiers. Study design, operational, and transparency-related features were assessed as predictors of time to publication, defined as the interval from study completion to first publication, using Cox proportional hazards model.

COVID-19 trials had the highest publication rate (49.6%), followed by CVD (42.3%) and cancer (32.9%), likely reflecting pandemic-related prioritization. Faster publication was associated with larger enrollment, more sites, result posting, randomization, DMC presence, and higher blinding levels (all p < 0.05). Slower publication was linked to supportive care or diagnostic trials (CVD), basic science (cancer), and later COVID-19 trial completion. In subgroups, U.S. facility presence (CVD) and phase 3 design (cancer) predicted faster publication, while healthy volunteer inclusion (CVD) predicted slower publication. Among DMC trials, more secondary outcomes were linked to faster publication across all disease areas.

Key study design and operational factors consistently predict whether and when trials are published. Strengthening methodological rigor, result reporting, and multi-site collaboration may accelerate timely dissemination into peer-reviewed literature.