Abstract
How large is the industry-specific disclosure gap inside ClinicalTrials.gov? Using the live ClinicalTrials.gov API and Python code shared on GitHub for reproducibility, we analysed a 29 March 2026 full-registry snapshot, focusing on 128,464 industry-linked studies and 87,296 closed interventional industry studies. We derived omission flags for missing results, missing actual enrollment, missing IPD statements, missing publication links, and missing detailed descriptions, keeping sponsor-level counts so rate-based and absolute backlog silence could be read together across firms globally. Among older closed interventional industry studies, 58.1 percent had no posted results, leaving 44,007 unresolved two-year no-results records in the industry bucket alone. The biggest backlogs sat with GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim, Sanofi, and Pfizer, while several smaller sponsors exceeded 95 percent on the same rate metric. Industry records were also structurally sparse, with 63.2 percent lacking IPD statements, 66.6 percent lacking publication links, and 53.8 percent lacking detailed descriptions. These show registry-visible non-disclosure rather than legal breach.
References
Zarin DA, Tse T, Williams RJ, et al. Update on Trial Registration 11 Years after the ICMJE Policy Was Established. N Engl J Med. 2017;376(4):. PMID 28121511.
Anderson ML, Chiswell K, Peterson ED, et al. Compliance with results reporting at ClinicalTrials.gov. N Engl J Med. 2015;372(11):. PMID 25760355.
National Library of Medicine. ClinicalTrials.gov API v2 [Internet]. Bethesda (MD): NLM; data snapshot accessed 29 March 2026. https://clinicaltrials.gov/data-api/api.
Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. doi:10.1136/bmj.n71. PMID 33782057.
Borenstein M, Hedges LV, Higgins JPT, Rothstein HR. Introduction to Meta-Analysis. 2nd ed. Chichester: Wiley; 2021.

This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2026 Mahmood Ahmad
