Enrollment and Retention of Men and Women in Health Services Research and Development Trials

Abstract Introduction Sex- and gender-specific science is essential to inform patient-centered, evidence-based care. Developing such evidence requires adequate inclusion of both women and men in trials. We sought to describe study participation of women and men in Department of Veterans Affairs Health Services Research and Development trials. Methods We identified recent health services research trials from one Health Services Research and Development Center of Innovation and compared the participation of women and men from trial recruitment to study completion. We also calculated the participation to prevalence ratio (PPR) by sex for each trial. Results We included eight trials that started recruitment between 2011 and 2014. Only one study purposefully attempted to boost the recruitment of women. Overall, the PPR for women ranged from 0.2 to 4.5, with seven studies having a PPR of greater than 1, indicating that women participated in these trials at proportions greater than their prevalence in the disease population within the Department of Veterans Affairs. The PPR for men ranged from 0.8 to 1.1. Retention was best with those studies that used administrative data for final outcomes assessment. No studies provided results stratified by sex or conducted analyses to explore treatment effect by sex. Conclusions At a single site, women participated in Health Services Research and Development trials at similar or greater rates to men without cross-study efforts to enrich the recruitment or retention of women. Adding strategic recruitment approaches could further boost the proportion of women in Department of Veterans Affairs trials and enable adequately powered sex-based analyses.