During a recent 10-year period, the incidence and risk factors of aneurysmal subarachnoid hemorrhage (SAH) in Shimokita area of Aomori prefecture was investigated. A total of 195 patients were registere, and the age-adjusted annual incidence was 20.7 per 100, 000 population. The age-specific annual incidences ranged from 32 to 40 per 100, 000 population at the age of 40-79 years in men. In Women, they became higher with increasing age, and revealed a peak, which was around from 60 to 70 per 100, 000 population after the sixth decade of life. This results suggested that Japan has much high incidence of SAH compared with other countries.
Case-control study was performed to evaluate the risk factors of SAH. Hypertension, cigarette smoking were a risk factor for both men and women. Alcohol consumption over 500 g/week was a risk factor for men, and familial history of SAH was a risk factor for women. The same factors can be risk factors in Japan as in other countries.
