Lifetime risk of stroke in the general male population.

OBJECTIVES: Most previous studies of incidence rates of stroke are from register studies, while data from prospective cohort studies are limited. The aim of the present study was to describe hazard rates, prevalence and cumulative proportion free from stroke during a lifelong follow-up of a representative sample of middle-aged men sampled from the general population. METHODS: A population-based sample of 855 men, all born in 1913, was investigated at 50 years of age and followed up with repeated medical examinations at age 54, 60, 67, 75 and 80. Data from hospital records and the Cause of Death Register were collected, and all stroke events during 48 years of follow-up were registered. Medical records were scrutinized in order to confirm and validate the stroke diagnoses. RESULTS: One man was excluded because of stroke prior to baseline, while 176 of the remaining 854 men (20.7%) suffered a first-ever stroke during follow-up. The total 5-year stroke risk (hazard rate) increased with age, from 3.54 (95% CI: 0-7.55) per 1000 persons at risk at age 50 years, to 119.05 (95% CI: 45.39-192.70) at age 90 years. The stroke prevalence peaked at age 80 and older, with about 120 cases per 1000 years of observation. The survival rate (cumulative proportion free from stroke) at age 98 was 50.0%. CONCLUSION: One out of five men in this population sample suffered a stroke of any type during follow-up from 50 to 98 years of age and the cumulative incidence was close to 50%.

Determinants of Stroke in a General Male Population.

Background and Purpose- To further improve preventive strategies against stroke, there is a need for epidemiological long-term studies. The study aimed at a prospective investigation of stroke determinants in the general male population. Methods- During a period of 48 years, from 50 to 98 years of age, a population-based sample of 854 men was followed using repeated medical examinations, lifestyle questionnaires, data from hospital records and the National Cause of Death Register. Results- Determinants of ischemic stroke were atrial fibrillation (hazard ratio [HR], 6.61; 95% CI, 4.47-9.77); mother dead from cardiovascular disease (HR, 1.53; 1.09-2.17); high education (HR, 0.81; 0.69-0.96); and high physical activity level during leisure time (HR, 0.68; 0.50-0.93). For hemorrhagic stroke heart rate (HR, 1.04; 1.01-1.06) and mother dead from stroke (HR, 3.56; 1.43-8.87) constituted an increased risk. Statistically significant determinants for all stroke were atrial fibrillation (HR, 5.34; 3.68-7.75); high diastolic blood pressure (HR, 1.02; 1.01-1.03); high body weight (HR, 0.96; 0.94-0.99); high educational level (HR, 0.79; 0.68-0.92); wide waist circumference (HR, 1.04; 1.01-1.07); smoking (HR, 1.25; 1.06-1.48); mother dead from cerebrovascular disease (HR, 1.43; 1.05-1.94); and diabetes mellitus (HR, 1.65; 1.02-2.68). Of all men diagnosed with atrial fibrillation, 88% had a stroke during follow-up. Conclusions- Atrial fibrillation was by far the strongest determinant of stroke during 48 years of follow-up in a male population sample followed until the age of 98 years. The results warrant improved prophylaxis through intense treatment of modifiable determinants.