Abstract WMP106: Why Are Women Less Represented in ICH Trials?

Abstract

Background: Fewer women than men tend to be enrolled in clinical trials of intracerebral hemorrhage (ICH). It is unclear whether this reflects lower prevalence of ICH in women, selection bias, poor recruitment efforts, or other factors. We undertook this study to examine differences between women and men in the reasons for exclusion from the iDEF (Intracerebral hemorrhage Deferoxamine) trial. Methods: The screen failure log included 29 different reasons for exclusion. Chi square statistics and p-values were used to evaluate whether women and men differed with regard to reason for screen failure. Findings: The iDEF trial enrolled 294 subjects; 38.5% were women. A total of 8776 subjects were screen failures. Sex was missing in 58. The remaining 8718 were included in this analysis; 3982 women (45.7%) and 4736 men (54.3%) (p<0.0001). The enrollment rates were 2.8% in women vs. 3.7% in men (p=0.01). We were unable to obtain consent in 1.3% of women vs 1.7% of men (p=0.1), and patients/families declined participation in 1.3% of women vs. 1.3% of men (p=0.9). More women than men failed screening because of age >80 (22.4% vs 12.6%) and pre-existing DNR/DNI (3.7% vs. 2.8%). Conversely, fewer women than men failed screening because inability to administer study drug within 24 hour due to late presentation (6.6% vs 7.8%), admission NIHSS score <6 (10.2% vs 13.2%), coagulopathy (5.3% vs 7.5%), inability to comply with the protocol (0.7% vs 1.3%), abnormal renal function (1.9% vs 2.9%), drug/alcohol abuse (1.7% vs 3.7%), and presentation with confirmed aspiration or pneumonia (1.1% vs 1.8%).These differences were statistically significant. Interpretation: Results from this multi-center, prospective, ICH trial indicate that lower rates of women enrollment may be attributed to older age and higher rates of pre-existing DNR/DNI orders. Inability to obtain consent or declining participation was similar between women and men, arguing against selection bias. Our findings should be confirmed in other ICH trials to determine if additional efforts are needed to improve women’s participation in future studies. Funding: US National Institutes of Health and US National Institute of Neurological Disorders and Stroke (U01NS074425)