The Current State of Timely Results Reporting Among Hypertension Trials on ClinicalTrials.gov: A Cross-Sectional Meta-Research Analysis

Objectives: To characterize how completely and promptly summary results are reported for registered hypertension trials on ClinicalTrials.gov, and whether reporting correlates with the observable obligation to report. Methods: Cross-sectional analysis of completed or terminated interventional trials for hypertension, retrieved through the ClinicalTrials.gov API version 2. Trials required a primary completion date of type ACTUAL at least 12 months before extraction. Reporting was timed from primary completion to first results submission and classified as timely at 365 days or fewer. Applicability was approximated requiring interventional design, phase 2 or later, a United States site, and an FDA-regulated drug or device, assigned flag-confirmed or inferred. Proportions are reported with Wilson 95% confidence intervals, time to reporting by Kaplan-Meier, and adjusted associations by logistic regression clustered on lead sponsor. Results: Of 5,851 trials, 5,396 were due to report. Timely reporting was 9.1% (95% CI 8.3-9.9) and any-time reporting 28.8% (95% CI 27.6-30.0). Reporting was graded by applicability, with flag-confirmed trials reporting timely at 36.9% (95% CI 31.6-42.5) and non-applicable trials at 6.3% (95% CI 5.6-7.1). A United States site carried the strongest adjusted association with timely reporting (OR 4.03, 95% CI 2.99-5.42). Among unreported trials, 7.8% had a sponsor-tagged publication and 36.4% under a broader definition. Conclusion: Prompt registry reporting of hypertension trial results remains uncommon, and reporting is most closely associated with the observable obligation to report.