Class IIa The weight of evidence or opinion is in favor of the procedure or treatment. Class IIb Usefulness/efficacy is less well established by evidence or opinion. Class III Conditions for which there is evidence and/ or general agreement that the procedure or treatment is not useful/effective and in some cases may be harmful. Therapeutic recommendations Level of Evidence A Data derived from multiple randomized clinical trials or meta-analyses Level of Evidence B Data derived from a single randomized trial or nonrandomized studies Level of Evidence C Consensus opinion of experts, case studies, or standard of care Diagnostic recommendations Level of Evidence A Data derived from multiple prospective cohort studies using a reference standard applied by a masked evaluator Level of Evidence B Data derived from a single grade A study or 1 or more case-control studies, or studies using a reference standard applied by an unmasked evaluator Level of Evidence C Consensus opinion of experts AHA/ASA indicates American Heart Association/American Stroke Association. Bushnell et al Guidelines for Prevention of Stroke in Women 1549 Age-specific stroke mortality is higher for men than women for all age groups except 85 years, and this pattern is con- sistent across all racial/ethnic groups (Figures 1 and 2).1,2,59 In 2010, age-adjusted stroke mortality (based on International Classification of Diseases, 10th Revision, codes I60 I69) for women was 38.3 per 100000 compared with 39.3 per 100000 for men (relative risk [RR], 0.97).59 For most of the past century, age-adjusted stroke mortality rates declined dra- matically in the United States,60 and between 1996 and 2005, these declines were marginally greater for men ( 28.2%) than Stroke is a major cause of death world- wide, accounting for an estimated 10% of all deaths in 2002. 