ClinicalTrials.gov is a Web based resource maintained by the U.S. National Library of Medicine (NLM) at the National Institutes of Health (NIH). The site contains information from almost 300,000 privately and publicly funded clinical studies from across the U.S. as well as 208 countries and is updated daily. The site defines a clinical study as “research using human volunteers that is intended to add to medical knowledge”.

The primary users of ClinicalTrials.gov are patients, their families and caregivers, medical practitioners, and medical researchers. The site serves several functions and is divided into four major categories.

Find Studies

Users can locate studies using specific search criteria or browse studies by topic (condition or disease). Patients or family members can learn about new treatments being considered as well as studies that are recruiting participants. Researchers can use the site to stay up to date on current developments, identify areas for further research, and identify potential collaborators.

With a basic search (below), users can locate studies by status (recruiting/not yet recruiting or all studies), condition or disease, other terms, and by location (including specific distance from a particular city).

The advanced search offers many additional options. A few examples include, searching by specific study type, studies with or without results, specific recruitment status, expanded access status (expanded access is a way for patients with a serious condition to obtain access to a medical product that has not been approved by the U.S. Food and Drug Association), eligibility criteria, study dates, as well as many other options for targeted searching.

This portion of the site also includes information on how to search, use search results, find results of studies, and read a study record.

ClinicalTrials.gov study records can be lengthy and detailed containing information about the description of a study, study design, interventions, outcome measures, eligibility criteria, contacts and locations, and further information. A study record’s, ClinicalTrials.gov Identifier, or NCT number (https://www.nlm.nih.gov/bsd/policy/clin_trials.html) can be used to locate related publications in PubMed, and these publications also appear at the bottom of the record.

Learn about Studies

Here users can learn specifics about what clinical studies are, for example, who conducts them, where they take place, what purpose they serve, as well as how to participate. This portion of the site also contains a glossary, providing definitions of common site terms.

Submit Studies

Geared towards researchers, this portion of the site contains specifics on how to submit their own studies. It includes a depth of training and support materials.

Resources

Advanced users might want to explore various tools and data provided by the site. For example, one can locate statistics and download study records for analysis.

Eric Snajdr, Associate Librarian, University Library, Indiana University – Purdue University, Indianapolis

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