Types of Registered Studies

This table shows the number and types of studies that are registered and for which results are available on ClinicalTrials.gov.

* A study may include more than one type of intervention (that is, a single study may be counted more than once). Because of this, the sum of counts by type of intervention do not equal the total number of interventional studies.
** A total of 539 applicable device clinical trials were submitted as "delayed posting" under the Food and Drug Administration Amendments Act of 2007 (FDAAA). That is, the Responsible Party has indicated that such a trial includes a device not previously approved or cleared by the U.S. FDA for any use. These are not included in the count of trials with at least one device.
*** Results are only required to be submitted for certain studies. For example, results submission is generally not required for observational studies; trials completed before 2008; and trials that include drugs, biologics, or devices not previously approved by the U.S. FDA for any use.

N/A = not applicable

See locations of the recruiting studies here, locations of registered studies here, and numbers of registered studies over time here.