Evaluating the Revised National Institutes of Health Clinical Trial Definition Impact on Recruitment Progress.

Background: The National Institutes of Health (NIH) announced a revised, expanded definition of "clinical trial" in 2014 to improve trial identification and administrative compliance. Some stakeholders voiced concerns that the policy added administrative burden potentially slowing research progress.

Methods: This quasi-experimental study examined the difference-in-differences impact of the new NIH clinical trial definition policy on participant recruitment progress in grants funded by the National Institute of Mental Health (NIMH).

Results: 132 funded clinical trial grants were identified. While more grants were identified as clinical trials under the revised definition, the difference-in-differences in recruitment progress before and after the policy change was not statistically significant.

Conclusions: The revised NIH clinical trial definition had no clear effect on recruitment progress in newly-identified NIMH-funded clinical trials as compared to traditionally-identified clinical trials. Concerns that administrative delays and burden could impact study progress may be alleviated by these initial results.