Mahmood Ahmad
Tahir Heart Institute
author@example.com

CT.gov U.S. Versus Global Gap

How different are ClinicalTrials.gov reporting gaps when older closed interventional studies are grouped into U.S.-only, mixed U.S.-global, non-U.S., and no-country buckets? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot and assigned each study to a geography bucket using recorded country locations. The project compares two-year no-results rates, ghost-protocol rates, visible shares, and sponsor-class contrasts across U.S.-only, U.S.-plus-non-U.S., non-U.S., and missing-country records. U.S.-plus-non-U.S. studies were the cleanest bucket at 30.2 percent no results, versus 55.8 percent for U.S.-only studies and 88.7 percent for studies with no U.S. location. No-country records also remained obscured at 80.9 percent no results and 53.6 percent ghost protocols, while mixed U.S.-global studies reached 46.3 percent full visibility. Geography bucket therefore behaves like a visibility classifier, and cross-border participation looks associated with cleaner registry surfaces than domestic-only or non-U.S.-only portfolios. Country buckets reflect recorded locations rather than verified enrollment shares, sponsor domicile, or legal reporting duties.

Outside Notes

Type: methods
Primary estimand: 2-year no-results rate across U.S./non-U.S. geography buckets among eligible older CT.gov studies
App: CT.gov U.S. Versus Global Gap dashboard
Data: 249,507 eligible older closed interventional studies grouped into U.S.-only, mixed, non-U.S., and no-country buckets
Code: https://github.com/mahmood726-cyber/ctgov-us-vs-global-gap
Version: 1.0.0
Validation: FULL REGISTRY RUN

References

1. ClinicalTrials.gov API v2. National Library of Medicine. Accessed March 29, 2026.
2. Zarin DA, Tse T, Williams RJ, Carr S. Trial reporting in ClinicalTrials.gov. N Engl J Med. 2016;375(20):1998-2004.
3. DeVito NJ, Bacon S, Goldacre B. Compliance with legal requirement to report clinical trial results on ClinicalTrials.gov: a cohort study. Lancet. 2020;395(10221):361-369.