CT.gov Country-Condition Hiddenness
2026-03-29 | full-registry ct.gov audit | plots, figures, and e156 bundle
Series
E156 Micro-Paper

CT.gov Country-Condition Hiddenness

A 156-word micro-paper on how disease-specific country footprints map onto hiddenness in older CT.gov studies.

Oncology
Cardiovascular
Metabolic
Named countries

Paper

Condition families are not geographically uniform. Their visibility profile changes once specific country footprints are named.

Reading note

Which disease-country cells look quietest on ClinicalTrials.gov once older closed interventional studies are split simultaneously by condition family and named study location? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot and exploded named-country involvement within selected condition families. The project compares two-year no-results rates, ghost-protocol rates, and visible shares for oncology, cardiovascular, and metabolic studies across country-condition cells with at least 400 studies. Oncology studies involving China reached 79.0 percent no results versus 52.6 percent for oncology studies involving the United States. Cardiovascular studies involving Egypt reached 95.9 percent no results, while metabolic studies involving China reached 78.9 percent and Denmark 79.6 percent. Disease and geography therefore interact rather than add independently, because the same condition family looks materially different once specific country footprints are named inside the same nominal therapeutic area. Country-condition cells reflect recorded study locations rather than country-specific enrollment shares, sponsor domicile, or national reporting mandates.

Oncology Poland visible
53.0%
Cleaner oncology country
Cardio China ghosts
38.8%
Selected cell
Cardio Egypt visible
3.6%
Results plus publication
Metabolic Spain visible
35.0%
Cleaner metabolic cell