ClinicalTrials.gov
Definition
The US National Library of Medicine's public registry of clinical studies. Comparing a registered protocol against the published paper is how a switched endpoint is caught.
Terms used in this definition
Other entries this definition refers to.
What this means for research sourcing
Understanding evidence quality helps researchers prioritize compounds. Volta's research library summarizes the literature behind stocked compounds.
Related Terms in Evidence & Research
NCT Number
The identifier every study registered on ClinicalTrials.gov carries, in the form NCT followed by eight digits. It resolves to the protocol, the enrolment status and, where posted, the results.
PubMed
The US National Library of Medicine's free index of biomedical literature, covering more than 30 million citations. A reference that resolves to a PubMed, PMC or DOI record can be checked; one that does not, cannot.
Cardiovascular Outcomes Trial
A large trial powered to detect differences in events such as myocardial infarction, stroke and cardiovascular death rather than in a laboratory marker. It is the design regulators require before a cardiovascular benefit may be claimed.
Estimand
A precise statement of what a trial is estimating: the population, the endpoint, and how events such as discontinuation are handled. Two analyses of one dataset can differ because they answer different estimands rather than because one is wrong.
Adherence
The extent to which participants followed the assigned protocol. Low adherence pulls a result toward no difference, so it is reported alongside the outcome rather than treated as a footnote.
Experimental Model
The system a finding was produced in: a cell line, an isolated tissue, an animal strain, or human participants. It bounds what the finding supports, and the gap between a cultured cell and an organism is where most translation failures occur.
Clinical Trial
A study testing an intervention in human volunteers under a protocol fixed before enrolment. The protocol, not the published paper, is what defines the question the trial was built to answer.
Randomized Controlled Trial (RCT)
A study in which participants are allocated to arms by chance, so that known and unknown differences between groups even out. It is the strongest single-study design for showing that an intervention caused an outcome.