In 2007, the US Food and Drug Administration (FDA) issued the US FDA Amendments Act (FDAAA), in which it stated that all clinical trials of FDA-regulated products must be registered with, and results reported on, ClinicalTrials.gov. The aim was to mitigate selective clinical trial registration and reporting, but has the FDAAA achieved this?
Phillips et al. recently published an article in Trials that investigates this question by analysing efficacy trials supporting new FDA approvals for cardiovascular disease or diabetes, before and after the FDAAA mandate. The authors used the ClinicalTrials.gov and PubMed databases, as well as publicly available FDA documents, to evaluate trial registration, reporting of results, and publication. They also compared the findings in FDA summaries to those reported in PubMed publications.
Of the 183 trials identified by the authors, 151 (83%) were registered on ClinicalTrials.gov. The proportion of registered trials increased from 70% pre-FDAAA to 100% post-FDAAA. The impact of FDAAA was also apparent in the proportion of trials with published results, with 89% published pre-FDAAA versus 97% after. Concordance rates between FDA summaries and published articles also improved, with 84% of findings in agreement pre-FDAAA and 97% in agreement post-FDAAA.
Overall, it would appear that the FDAAA has had a positive impact on trial registration and outcome reporting and publication. Although this study only looked at FDA-approved agents for cardiovascular disease or diabetes, the results are encouraging in this era of transparency. The authors point out, however, that many historical trials remain unpublished.