Recent epidemiological trends of stroke

Rapid increase in aged population and westernization of lifestyle have modified epidemiological status of stroke. The purpose of this study is to analyze changing trends of stroke epidemiology in South Korea.

We reviewed retrospectively medical records of 1,124 cases diagnosed as stroke among 54,534 patients who visited the Emergency Medical Center at our hospital from January 1994 to December 1996 (Group A). Also, we evaluated 1,705 cases diagnosed as stroke among 55,381 patients who visited to the same hospital from January 2003 to December 2005 (Group B). The variable features of stroke, such as age, sex, seasonal variation and distribution of stroke subtypes were studied by comparing group A with B.

In group A, hemorrhagic stroke (67.9%) was more prevalent than ischemic stroke (32.1%). However, group B showed that the ratio of hemorrhagic stroke (40.3%) to ischemic stroke (59.6%) has been reversed. The highest incidence of stroke was noted in their sixties and seventies of age in group B, which was older than that of group A. In group A, male ischemic stroke (IS) patients outnumbered female patients (1.26:1). Moreover, this gender disproportion became higher in group B (1.53:1). In group A, the number of male intracerebral hermorrhage (ICH) patients were similar to that of female patients (0.97:1). However, male ICH patients outnumbered female patients in group B (1.23:1). As for subarachnoid hemorrhage (SAH), female patients outnumbered male patients more than two-fold in both groups. Both groups showed that the occurrence of ischemic stroke was highest in summer, but that of hemorrhagic stroke was the highest in winter.

This study showed the changing trends of stroke in its distribution of subtypes. Multicenter prospective study using stroke registry would be required for the determination of national epidemiologic trends.