Attributable risk of common and rare determinants of subarachnoid hemorrhage

Background and Purpose-Smoking, hypertension, alcohol consumption, autosoma l dominant polycystic kidney disease (ADPKD), and positive family history f or subarachnoid hemorrhage (SAH) are well-known risk factors for SAH, For e ffective prevention, knowledge about the contribution of these risk factors to the overall occurrence of SAH in the general population is pivotal. We therefore investigated the population attributable risks of the risk factor s for SAH. Methods-We retrieved the relative risk and prevalence of established risk f actors for SAH from the literature and calculated the population attributab le risks of these risk factors. Results-Drinking alcohol 100 to 299 g/wk accounted for 11% of the cases of SAH, drinking alcohol greater than or equal to 300 g/wk accounted for 21%, and smoking accounted for 20%. An additional 17% of the cases could be attr ibuted to hypertension, 11% to a positive family history for SAH, and 0.3% to ADPKD. Conclusions-Screening and preventive treatment of patients with familial pr eponderance of SAH alone will cause a modest reduction of the incidence of SAH in the general population. Further reduction can be achieved by reducin g the prevalence of the modifiable risk factors alcohol consumption, smokin g, and hypertension.