Meschia et al Guidelines for the Primary Prevention of Stroke 3831 891. Fowkes FG, Price JF, Stewart MC, Butcher I, Leng GC, Pell AC, Sandercock PA, Fox KA, Lowe GD, Murray GD; Aspirin for Asymptomatic Atherosclerosis Trialists. Aspirin for preven- tion of cardiovascular events in a general population screened for a low ankle brachial index: a randomized controlled trial. JAMA. 2010;303:841 848. 892. Uchiyama S, Demaerschalk BM, Goto S, Shinohara Y, Gotoh F, Stone WM, Money SR, Kwon SU. Stroke prevention by cilostazol in patients with atherothrombosis: meta-analysis of placebo-controlled randomized trials. J Stroke Cerebrovasc Dis. 2009;18:482 490. 893. Jardine MJ, Ninomiya T, Perkovic V, Cass A, Turnbull F, Gallagher MP, Zoungas S, Lambers Heerspink HJ, Chalmers J, Zanchetti A. Aspirin is beneficial in hypertensive patients with chronic kidney disease: a post-hoc subgroup analysis of a randomized controlled trial. J Am Coll Cardiol. 2010;56:956 965. 894. Centers for Disease Control and Prevention. Emergency department vis- its within the past 12 months among adults aged 18 and over, by selected characteristics: United States, selected years 1997 2011. http://www. cdc.gov/nchs/data/hus/2011/094.pdf. Accessed March 14, 2013. 895. Hsia RY, Kellermann AL, Shen YC. Factors associated with clo- sures of emergency departments in the United States. JAMA. 2011;305:1978 1985. 896. Babcock Irvin C, Wyer PC, Gerson LW. Preventive care in the emer- gency department, part II: clinical preventive services: an emergency medicine evidence-based review: Society for Academic Emergency Medicine Public Health and Education Task Force Preventive Services Work Group. Acad Emerg Med. 2000;7:1042 1054. 897. Bernstein SL, Haukoos JS. Public health, prevention, and emergency medicine: a critical juxtaposition. Acad Emerg Med. 2008;15:190 193. 898. Reeves MJ, Hogan JG, Rafferty AP. Knowledge of stroke risk factors and warning signs among Michigan adults. Neurology. 2002;59:1547 1552. 899. Marsden C, Pinell MC, Joyce SM. 