Although randomized trials are unavailable, there may be a very clear clinical consensus that a particular test or therapy is useful or effective. *Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as sex, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. For comparative effectiveness recommendations (Class I and IIa; Level of Evidence A and B only), studies that support the use of comparator verbs should involve direct comparisons of the treatments or strategies being evaluated. of ICH has been reported to be lower in women than men in but not all42 studies. Differences by race/ethnicity have been noted, with higher ICH incidence rates in blacks and in Hispanics than whites for both women Increased Prevalence of SAH in Women: Risks Related to Cerebral Aneurysms There has been significant debate about the potential cause of the increased risk of SAH in women. 