Understanding Differences in Enrollment Outcomes among High-Risk Populations Recruited to a Phase IIb HIV Vaccine Trial

• Authors: Paula M. Frew, Emory University; Carlos Del Rio, Emory University; Lu Lu, Emory University; Sarah Clifton, Emory University; Mark Mulligan, Emory University
• Journal Title: Journal of Acquired Immune Deficiency Syndromes
• Volume: Volume 50, Number 3
• Publisher: Lippincott, Williams & Wilkins | 2009-03-01, Pages 314-319
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1097/QAI.0b013e3181945eec
• Subjects: Health Sciences, Public Health
• Keywords: HIV Vaccine; Willingness-to-Participate; Recruitment; Retention; Women; Minorities

Abstract

Background The Step Study, a Phase IIb HIV vaccine proof of concept study, enrolled approximately 3,000 persons in Clade B regions. The Atlanta site sought to enroll a diverse population. This prospective cohort study examined key factors associated with participant enrollment. Methods We obtained participant information (e.g., sociodemographic, medical) and followed outcomes from 2005 to 2007. Of the 810 potential “Step Study” participants, 340 cases were analyzed. Results The recruitment strategy generated strong interest among minorities with 37% eligible following prescreening, yet 25% of the minorities enrolled. However, the percentage of whites increased from 62% eligible (prescreened sample) to 75% enrolled. The regression model was significant with educational level being an enrollment predictor (p = 0.0023). Those with at least a bachelor’s degree were more likely to enroll compared to those with a K-12 education or some college (OR = 2.424, 95% CI = 1.372–4.281, p < 0.01). White race was also a significant factor (OR=2.330; 95% CI = 1.241–4.375, p < 0.01). No difference in enrollment was observed among recruitment approaches, Pearson χ2 (2, N = 336) = 5.286, p = 0.07. Conclusions The results from this study indicate that women, minorities, and those with lower educational attainment were less likely to enroll in an HIV vaccine efficacy study at our site. The findings highlight an important consideration on the role of health literacy to sustain participation of eligible minorities in HIV vaccine trials.