Stroke in the Lehigh Valley: incidence based on a community-wide hospital register.

Since July 1982 a population-based study of stroke has been carried out in the Lehigh Valley, a region in Pennsylvania and New Jersey, USA, with 580,000 people. During the first year, the annual incidence rates of stroke and transient ischemic attack were 167 and 49 per 100,000 population, respectively. Cerebral thrombosis, embolus, cerebral hemorrhage and subarachnoid hemorrhage accounted for 76, 13, 8 and 3% of the strokes, respectively. The overall incidence rate and distribution of stroke by type agree well with other population-based studies. The large size of the population in the Lehigh Valley means that information on the epidemiology of stroke, as well as the effects of various therapies on stroke frequency and outcome, can be collected in a shorter period of time than in most other communities studied to date. Finally, an assessment of concordance in diagnosis between attending physicians and a neurologist using standardized criteria was possible for the entire community.