In a study appearing in the March 22/29 issue of JAMA, Ann Marie Navar, M.D., Ph.D., of Duke University Medical Center, Durham, N.C., and colleagues examined how shared clinical trial data are being used. Concerns over bias in clinical trial reporting have stimulated calls for more open data sharing. In response, multiple pharmaceutical companies have created mechanisms for investigators to access patient-level clinical trials data.

The researchers evaluated how many clinical trials were publicly available to investigators through 3 open access platforms, and found that a total of 3,255 clinical trials were available in the platforms. The median number of trials requested by each proposal was 2. Only 505 unique trials (15.5 percent of available trials) had ever been requested. "Reasons for underutilization of clinical trials data may include lack of knowledge about these resources, possibly due to lack of publication of results from proposals, or lack of funding to support analyses."

"Early use of platforms designed to provide access to individual patient data, developed to increase transparency of clinical trial data, has been limited. Availability of shared clinical trial data should be promoted and use of individual patient data for validation studies encouraged."