Screening and Enrollment by Sex in Human Immunodeficiency Virus Clinical Trials in the United States

Clinical Infectious Diseases, September 2019

While women represent about one-quarter of adults living with HIV in the United States and over half of people living with HIV worldwide, many HIV clinical trials enroll fewer than 25% women. ACTG DACS 325 sought to assess how people living with HIV are recruited into the network’s clinical trials and whether ACTG enrolled proportionally lower percentages of women than men from the United States (and if so, why).

This analysis included all ACTG trials recruiting people living with HIV in the United States from 2003 (when the screening database started) through 2013. Researchers were not able to investigate gender identity, as it was not added to the ACTG screening questions until 2017. Data from 31 trials recruiting at 99 clinical research sites across the United States resulted in information on almost 11,000 participants. About one fifth (19%) of those screened were women living with HIV. Among those assessed, 28% did not enroll, which was only slightly higher than the 27% no enroll rate among men. These results did not differ when considering race, ethnicity, or age. The most common reasons for people not enrolling were not meeting trial requirements or persons opting-out and these reasons did not differ by sex. Pregnancy, breastfeeding, and trial contraceptive requirements were rarely reported as reasons to not enroll, though researchers speculate that women for whom these requirements applied may have been excluded (or excluded themselves) from trial consideration prior to screening.

Because the data around some of the factors relevant to participant recruitment (for example, childcare access, transportation, or participant reimbursement) were not available in the database, researchers were not able to address sex differences in the role of these factors in recruitment. Since there was no evidence for a significantly higher trial screen-out for women than men in this analysis, investigators concluded that approaching more women to screen may increase female representation in ACTG trials. This important analysis indicates that a strategy to expand eligibility and approach women prior to screening to assess barriers will help us in the important goal of increasing enrollment of women in all HIV clinical trials.

Smeaton, L.M., Kacanek, D., Mykhalchenko, K., Coughlin, K., Klingman, K.L., Koletar, S.L., Barr, E., Collier, A.C. Screening and Enrollment by Sex in HIV Clinical Trials in the United States. Clin Infect Dis. 2019 Sep 29;. doi: 10.1093/cid/ciz959. [Epub ahead of print] PubMed PMID: 31563942.