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 One hundred thirty-two 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.