Introduction: To increase the transparency of clinical trial information, U.S. Congress passed the Food and Drug Administration (FDA) Amendments Act of 2007, which expanded prior legislation to mandate inclusion of specific trial characteristics, such as funding source and gender demographics, in a new basic results section on ClinicalTrials.gov. Few studies have examined the extent to which key demographic characteristics such as sex and race/ethnicity are reported for neurological trials on ClinicalTrials.gov.
Methods: As part of the National Initiative for Minority Involvement in Neurological Clinical Trials (NIMICT), we systematically identified neurological clinical trials on ClinicalTrials.gov (for stroke, epilepsy, Alzheimer’s Disease [AD]) and examined the proportion that reported sex, race, and ethnicity (Hispanic/Latino or not) of study participants. We used the website’s advanced search feature to evaluate demographic information reported from trials conducted between 1999 and 2015. We first calculated frequencies of trials reporting these characteristics, then assessed differences in reporting of each characteristic (yes/no) by condition (stroke, epilepsy, AD) and between trials conducted before and after the basic results section update (pre- and post-2008) using chi-square tests.
Results: Our sample comprised 251,847 subjects across 393 trials (147 stroke, 127 epilepsy, 115 AD). Overall, sex was reported for nearly all trials (99.0%), while reporting of race and ethnicity was low (ethnicity: 14.0%, race: 19.8%). Reporting of these characteristics did not differ significantly across the three conditions or between periods preceding and following the FDA act.
Conclusion: While ClinicalTrials.gov mandates reporting of sex, it does not require reporting of race/ethnicity, and few trials report these characteristics. This lack of information prevents understanding of neurological trial participation and how interventions might impact patients differently by race/ethnicity. Mandatory reporting of race/ethnicity would enhance transparency and increase awareness of the limited participation of racial/ethnic minorities-who suffer disproportionately from neurological diseases-in neurological trials.