About the ClinicalTrials.gov Results Database


As of September 2008, the ClinicalTrials.gov Results Database allows data providers to report summary results of registered clinical trials and observational studies. Results are reported in a standard, tabular format that consists of the following:
  • Participant Flow
  • Baseline Characteristics
  • Outcome Measures and Statistical Analyses
  • Adverse Events Information
  • Administrative Information
ClinicalTrials.gov reviews results submissions to ensure that they are clear and informative prior to public posting (review criteria). However, ClinicalTrials.gov cannot ensure scientific accuracy. Each data provider is responsible for ensuring that the information is accurate and complete.

To search and find posted results information, use the Advanced Search page and set the Study Results search field to "Studies With Results."

Results Reporting Requirements Under U.S. Federal Law


While results information may be submitted for any registered study, US Public Law 110-85 (Food and Drug Administration Amendments Act of 2007 or FDAAA), Title VIII, Section 801 mandates that a "responsible party" (i.e., the study sponsor or designated principal investigator) register and report results of certain "applicable clinical trials" that were initiated or ongoing as of September 27, 2007:
  • Trials of Drugs and Biologics: Controlled, clinical investigations, other than Phase I investigations, of a product subject to FDA regulation
  • Trials of Devices: Controlled trials with health outcomes of a product subject to FDA regulation (other than small feasibility studies) and pediatric postmarket surveillance studies.
"Applicable clinical trials" generally include interventional studies (with one or more arms) of drugs, biological products, or devices that are subject to FDA regulation, meaning that the trial has one or more sites in the U.S, involves a drug, biologic, or device that is manufactured in the US (or its territories), or is conducted under an investigational new drug application (IND) or investigational device exemption (IDE).


In general, a responsible party is required to submit "basic results" information not later than one year after the "primary completion date" or date that the final subject was examined or received an intervention for the purposes of final collection of data for the primary outcome, whether the clinical trial concluded according to the prespecified protocol or was terminated. (Note that, if submitted by the data provider, the "primary completion date" is listed in the study protocol record.)

Delayed Submission

The law allows for delayed submission of results information with certification. A responsible party may submit a certification for delayed submission of results information for an applicable clinical trial that is:
  • Completed before the drug or device is initially approved, licensed, or cleared by the FDA ("seeking initial approval")
  • Studying a new use of an FDA-approved drug or device (i.e., a use not included in the labeling) for which the manufacturer of a drug or device is the sponsor of the trial and has filed or will file within a year an application to the FDA for approval or clearance of that use ("seeking approval of a new use")
The law also allows the NIH to provide an extension of the deadline for submission of results information for an applicable clinical trial if the responsible party submits a written request that demonstrates good cause for the extension and provides an estimate of the date on which the results information will be submitted. Pending publication is not considered a good cause for an extension.

Displaying Results Records

ClinicalTrials.gov organizes information for each registered study as an integrated unit, displaying the study protocol record and, if available, the corresponding results record under different tabs on the same page to facilitate cross-referencing.

No Study Results Posted

When results are not available for a study, the results record tab is labeled, "No Study Results Posted." Results may not be posted for any of the following reasons:
  • The study is still ongoing
  • The study may not be subject to the Federal results reporting requirements
  • The study is completed, but the deadline for results reporting has not been reached
  • The results have been submitted, but have not yet been posted (e.g., pending review by ClinicalTrials.gov)
  • Submission of results information has been delayed with certification
  • A request for extending the submission deadline has been submitted to NIH
Has Study Results

When results are available publicly for a study, the status column in the "List Results" tab (search results list) is annotated, "Has Results," and the results record tab is labeled, "Study Results." The summary results will be displayed in the tabular format, a s described above.

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