Mahmood Ahmad
Tahir Heart Institute
author@example.com

CT.gov Completion Cohort Debt

Do newer ClinicalTrials.gov completion cohorts look more transparent once every study has had at least two years to report? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot and grouped them by primary completion year and broader completion eras. For each cohort we estimated two-year no-results rates, ghost-protocol rates defined as missing results plus missing publication links, and the share with both signals visible. The 2008-2012 completion era showed a 64.4 percent no-results rate and a 38.8 percent ghost-protocol rate. By 2021-2024, the comparable rates had worsened to 77.0 percent and 46.7 percent, while the fully visible share fell to 10.8 percent. Year-level summaries showed the same recent drift, indicating that eligibility alone does not erase newer registry silence across successive completion cohorts. These cohort comparisons are descriptive and can reflect changing trial mix, backfilling, and publication-linking practices as well as reporting behavior inside this still uneven public reporting system.

Outside Notes

Type: methods
Primary estimand: 2-year no-results rate by primary completion cohort among eligible older closed interventional studies
App: CT.gov Completion Cohort Debt dashboard
Data: Eligible older closed interventional studies grouped by primary completion year and completion era
Code: https://github.com/mahmood726-cyber/ctgov-completion-cohort-debt
Version: 1.0.0
Validation: FULL REGISTRY RUN

References

1. ClinicalTrials.gov API v2. National Library of Medicine. Accessed March 29, 2026.
2. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement. BMJ. 2021;372:n71.
3. Borenstein M, Hedges LV, Higgins JPT, Rothstein HR. Introduction to Meta-Analysis. 2nd ed. Wiley; 2021.

AI Disclosure

This work represents a compiler-generated evidence micro-publication built from structured registry data and deterministic summary code. AI was used as a constrained coding and drafting assistant for interface generation, packaging, and prose refinement, not as an autonomous author. The analytical choices, interpretation, and final outputs were reviewed by the author, who takes responsibility for the content.