CT.gov Intervention-Type Gap
2026-03-29 | full-registry ct.gov audit | plots, figures, and e156 bundle
Series
IndustrySponsor ClassesPhasesStructuralVisibilityCohortsConditionsConcentrationRule ErasPubMed AuditOncologyCardiovascularMetabolicSizeGeographyPurposeDelayArchitectureInterventionsCountriesStoppedOutcomesActual Fields
Intervention Dashboard

Declared intervention family is a strong visibility classifier inside older CT.gov studies

Drug studies dominate by stock, but declared family still matters: dietary-supplement, procedure, and behavioral studies remain far quieter than biological studies and multi-type designs.

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No results
Ghosts
Type mix
Largest families

Dashboard

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Intervention family turns a single backlog into several distinct visibility profiles, from biological to procedure-heavy quiet zones.

How to read the dashboard
Dietary no results
90.6%
Quietest large family
Procedure ghosts
48.1%
Neither visible
Single-type no results
74.0%
One intervention family
Multi-type visible
18.1%
Results plus publication
No-results by family
INTERVENTION FAMILIES2-year no-results rate by declared intervention familyDRUG62.6%OTHER82.8%DEVICE68.4%BEHAVIORAL81.1%PROCEDURE85.3%BIOLOGICAL58.5%DIETARY_SUPPLEMENT90.6%RADIATION65.7%DIAGNOSTIC_TEST85.9%COMBINATION_PRODUCT76.3%
Dietary-supplement, diagnostic-test, procedure, and behavioral studies all sit above drug and biological studies.
The gap is large enough that modality classification changes the story even before sponsor or phase enters the picture.
Ghost protocols by family
INTERVENTION GHOSTSGhost-protocol rate by declared intervention familyDRUG40.1%OTHER46.5%DEVICE40.8%BEHAVIORAL39.4%PROCEDURE48.1%BIOLOGICAL34.8%DIETARY_SUPPLEMENT50.2%RADIATION40.9%DIAGNOSTIC_TEST50.4%COMBINATION_PRODUCT44.1%
Procedure and dietary-supplement families also sit high on the full invisibility metric.
The ghost view matters because it collapses both missing results and missing publication links into one public-silence measure.
Single-type versus multi-type
TYPE-MIX CONTRASTVisibility contrast between single-type and multi-type studiesSingle-type no results74.0%Multi-type no results64.7%Single-type ghosts43.5%Multi-type ghosts37.5%
Studies declaring multiple intervention families are visibly cleaner than single-type studies on both main metrics.
That keeps the page from collapsing into a simple one-label ranking and adds a design-mixture layer.
Read Across Projects

Across The Series

Each project isolates a different dimension of registry opacity, but the point is the contrast between them, not a single leaderboard.

Industry
CT.gov Industry Disclosure Gap

Industry-focused missing-results stock, sponsor backlogs, and structural sparsity inside CT.gov.

Sponsor Classes
CT.gov Sponsor-Class Hiddenness

Sponsor-class comparisons on rate, stock, and structural hiddenness rather than one flattened ranking.

Phases
CT.gov Phase Reporting Gap

Phase-by-phase disclosure gaps showing how silence changes along the development pathway.

Structural
CT.gov Structural Missingness

Field-level missingness across publication links, IPD statements, descriptions, and locations.

Visibility
CT.gov Evidence Visibility Gap

Results-plus-publication visibility states showing how many older trials are fully visible, partly visible, or ghosted.

Cohorts
CT.gov Completion Cohort Debt

Completion-era reporting debt showing how older eligible cohorts drift on no-results and ghost-protocol rates.

Conditions
CT.gov Condition Hiddenness Map

Keyword-classified therapeutic-area hiddenness mapping across common condition families.

Concentration
CT.gov Sponsor Backlog Concentration

Concentration and inequality analysis showing how much unresolved stock sits inside a thin sponsor slice.

Rule Eras
CT.gov Rule-Era Reporting Gap

Policy-era comparisons across pre-FDAAA, FDAAA, and later CT.gov completion cohorts.

PubMed Audit
CT.gov Publication Undercount Audit

Sample-based external PubMed NCT audit testing how often CT.gov no-link records hide an external paper trail.

Oncology
CT.gov Oncology Hiddenness

Oncology-specific CT.gov hiddenness showing where cancer-trial stock, phases, and sponsors still go quiet.

Cardiovascular
CT.gov Cardiovascular Hiddenness

Cardiovascular CT.gov hiddenness showing how heart and vascular studies remain quiet across major phases and sponsors.

Metabolic
CT.gov Metabolic Hiddenness

Metabolic CT.gov hiddenness across obesity, diabetes, and related trial portfolios with large late-phase and NA stock.

Size
CT.gov Enrollment-Size Gap

Enrollment-size gradients showing how older small trials remain much quieter than larger registered studies.

Geography
CT.gov Geography-Scale Visibility

Site and country footprint analysis showing how larger trial geographies map onto much better public visibility.

Purpose
CT.gov Design-Purpose Hiddenness

Primary-purpose and allocation analysis showing which trial intents remain most obscured on CT.gov.

Delay
CT.gov Completion-Delay Debt

Registration-to-completion delay analysis showing short-cycle studies carry the heaviest reporting debt.

Architecture
CT.gov Trial-Architecture Gap

Arm-count and intervention-count analysis showing simpler trial architectures are often the quietest.

Countries
CT.gov Country Reporting Map

Named-country visibility analysis showing large geographic divides in older CT.gov reporting debt.

Stopped
CT.gov Stopped-Trial Disclosure Gap

Final-status analysis showing how withdrawn, suspended, and terminated studies remain structurally quieter than completed trials.

Outcomes
CT.gov Outcome-Density Gap

Outcome-count and outcome-description analysis showing sparse protocols are often the quietest CT.gov segment.

Actual Fields
CT.gov Actual-Field Discipline

Closed-study actual-field analysis showing missing actual dates and counts are a strong warning sign for opacity.

Source on GitHub | Project home | Dashboard