Clinical Trial Registration

The act of submitting a clinical trial's identifying and design information — sponsor, condition studied, intervention, key eligibility criteria, and primary/secondary outcome measures — to a recognized public clinical-trial registry (ClinicalTrials.gov or any other WHO ICTRP primary registry) so the trial's existence and design are publicly discoverable independent of whether or how its results are ultimately published. Registration identifies the trial before or during its conduct; posting the trial's results to the same registry after completion is a separate, later obligation (results reporting), not part of registration itself.

ByClinicalTrials.gov (National Library of Medicine, NIH)

· Last updated 10 Jul 2026

Worked examples

Is an instance

A pharmaceutical sponsor registers a Phase 2 drug trial on ClinicalTrials.gov before enrolling its first participant, receiving an NCT number that is then cited to identify the trial in any resulting journal manuscript and in the later results-reporting record.

Is an instance

An academic trial conducted primarily in the UK registers with ISRCTN — a WHO ICTRP-recognized primary registry — rather than ClinicalTrials.gov; this still satisfies ICMJE's registry-acceptability criteria, because those criteria require registration with any qualifying WHO primary registry, not specifically with ClinicalTrials.gov.

Looks similar, but isn't

Not an instance

Posting a trial protocol to a preprint server or the sponsoring institution's own website, even with a timestamp, is not registration in this sense — it is not captured in a structured, publicly searchable registry meeting the WHO Trial Registration Data Set, so it cannot be cited as satisfying ICMJE, FDAAA 801, or NIH registration requirements.

Not an instance

Pre-registering the hypotheses and statistical analysis plan of a study that is not itself a clinical trial (for example, a psychology lab experiment) on a general research-transparency platform such as OSF Preregistration or AsPredicted is pre-registration as a broader methodological practice — not clinical trial registration, which applies specifically to interventional trials recorded in a WHO/ICMJE/FDAAA-qualifying clinical-trial registry.

Clinical trial registration is the baseline transparency mechanism underlying most modern clinical-research policy: a trial cannot be selectively reported, quietly abandoned without a public trace, or have its design retroactively altered to fit favorable results if its existence, design, and pre-specified outcomes were already on the public record before it produced any data. This is the rationale cited by the International Committee of Medical Journal Editors (ICMJE) for its registration policy, in effect for trials beginning enrollment on or after 1 July 2005, and it underlies the separate, later U.S. statutory requirement created by FDAAA 801 (2007) and the companion NIH Policy on the Dissemination of NIH-Funded Clinical Trial Information (both effective 18 January 2017).

Registration is distinct from results reporting — posting outcome data to the same registry after the trial concludes — which is a separate obligation with its own deadline (12 months after primary completion, under FDAAA 801). It is also distinct from prospective registration specifically, i.e. completing registration before enrollment begins rather than retrospectively at manuscript submission; ICMJE’s policy requires the prospective form. And it is a narrower concept than general research pre-registration, which covers pre-specifying a study’s hypotheses and analysis plan across any research discipline, not only interventional clinical trials on a qualifying registry.

For the specific deadlines, enforcement mechanisms, and the genuine differences between ICMJE’s, FDAAA’s, and NIH’s definitions of which trials are covered, see CASRAI’s clinical trial registration and reporting compliance guide.

Use in your systems

JATS XML <role> element

xml

<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="Clinical Trial Registration"
      vocab-term-identifier="https://casrai.org/dictionary/term/clinical-trial-registration" />

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/clinical-trial-registration",
  "name": "Clinical Trial Registration",
  "identifier": "https://casrai.org/dictionary/term/clinical-trial-registration",
  "description": "The act of submitting a clinical trial's identifying and design information — sponsor, condition studied, intervention, key eligibility criteria, and primary/secondary outcome measures — to a recognized public clinical-trial registry (ClinicalTrials.gov or any other WHO ICTRP primary registry) so the trial's existence and design are publicly discoverable independent of whether or how its results are ultimately published. Registration identifies the trial before or during its conduct; posting the trial's results to the same registry after completion is a separate, later obligation (results reporting), not part of registration itself.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/compliance-regulatory#set",
  "url": "https://casrai.org/dictionary/term/clinical-trial-registration",
  "sameAs": [
    "https://clinicaltrials.gov/policy"
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "dateModified": "2026-07-10T01:49:37",
  "inLanguage": "en"
}