ClinicalTrials.gov

ClinicalTrials.gov is a registry and results database of clinical trials run by the United States National Library of Medicine (NLM) at the National Institutes of Health. It holds registrations from more than 444,000 trials conducted in 221 countries.^[1][2][3].

The site went online on February 29, 2000, following a mandate in the Food and Drug Administration Modernization Act of 1997, and was substantially expanded by the Food and Drug Administration Amendments Act of 2007 (FDAAA), which required registration and basic results reporting for many trials, with penalties for noncompliance.^[2]

What It Does

ClinicalTrials.gov lets sponsors and investigators register clinical studies and publish structured records covering purpose, eligibility criteria, locations, contacts, and study status, from recruitment through completion or termination. Sponsors of applicable drug and device trials are legally required to register under FDAAA Section 801.^[2]

For alternative-data users, the registry provides a structured, timestamped feed of research-and-development activity by pharmaceutical and biotechnology companies: new trial registrations, status changes (for example from recruiting to terminated), and summary results can signal pipeline progress before it appears in earnings or press releases.^[2]

Data And Methodology

Each trial record is administered by a record manager, who registers the trial before enrollment, updates its status as the study progresses, and uploads basic summary results via a web form or a compliant XML file once results are known or legal deadlines are met.^[2]

Records carry NCT identification numbers that can be linked to PubMed identifiers for published articles. Studies have found substantial gaps between registered trials and published results; a 2013 analysis of 8,907 interventional trials found 72.2% had no formally linked result article.^[2]

History

Congress mandated creation of the resource through the Food and Drug Administration Modernization Act of 1997, and NLM made ClinicalTrials.gov available to the public on February 29, 2000, initially focused on NIH-sponsored trials. The ICMJE's 2004 decision to require prior registration for journal publication, and FDAAA 801 in 2007, which mandated registration and results reporting with penalties for noncompliance, drove much broader industry participation.^[2]

Products And Data Access

Beyond the public search interface, the full registry content is available for bulk download as structured XML, supporting programmatic consumption and quantitative research.^[2]

The database for Aggregate Analysis of ClinicalTrials.gov (AACT), maintained with the Clinical Trials Transformation Initiative, offers a publicly available relational version of the data with normalized metadata to facilitate aggregate analysis across trials.^[2]

Compliance

Registration and reporting obligations derive from U.S. statute: results reporting became mandatory in September 2008 and adverse-event reporting in September 2009. Compliance has been uneven; a study of trials conducted between 2008 and 2012 found about half of those required to report had not done so, a fact relevant to any analyst using the registry as an exhaustive source.^[2]