—To prospectively examine the relationship of time since stopping smoking with risk of stroke in middle-aged women.
—An ongoing prospective cohort of women with 12 years' follow-up data (1976 to 1988), in which information on smoking habits was updated every 2 years by postal questionnaire.
—A total of 117 006 female registered nurses aged 30 to 55 years in 1976 and free of coronary heart disease, stroke, and cancer at baseline.
Main Outcome Measures.
—Incident strokes (fatal and nonfatal), further subdivided into ischemic stroke, subarachnoid hemorrhage, and cerebral hemorrhage.
—The age-adjusted relative risk of total stroke among current smokers compared with never smokers was 2.58 (95% confidence interval, 2.08 to 3.19). The corresponding relative risk among former smokers was 1.34 (95% confidence interval, 1.04 to 1.73). For total and ischemic stroke, the excess risks among former smokers largely disappeared from 2 to 4 years after cessation. The same patterns of decline were observed regardless of number of cigarettes smoked, the age at starting, or the presence of other risk factors for stroke.
—The risk of suffering a stroke among cigarette smokers declines soon after cessation and the benefits are independent of the age at starting and the number of cigarettes smoked per day.(JAMA. 1993;269:232-236)