[Stroke incidence in Asturias, 1990-1991].

BACKGROUND: Stroke, with a rate of 121/100,000 was the second cause of death in Asturias, Spain. Here we communicate the results of a population based stroke register in the oriental health districts of Asturias.
METHOD: The study took place between October 1, 1990 and May 30, 1991, covering a population of 652,549. Surveillance was both active and passive and included the public and private hospitals, and the primary health care. Death certificates could not be checked due to legal reasons. We defined case following the WHO criteria.
RESULTS: During the eight months of study 708 case occurred. The crude incidence rate of first stroke was 132.4/100,000 and that of any stroke, 162.7/100,000. The age adjusted incidence to the world population was, respectively, 61.3/100,000 and 73.6/100,000. There were no differences in the incidence across sexes. Age showed a strong effect in cerebral infarctation and less marked in intracerebral hemorrhage Infarcts are very rare in women before 50. Distribution of stroke type was: infarct: 77%; intracerebral hemorrhages: 14%: subarachnoid hemorrhage: 4% and unspecified stroke: 4%. Almost 50% of the strokes occurred in the morning hours, from 6:00 am to 12:00 am also during the cold season, winter and fall, the proportion of stroke was higher than during the warm season.
CONCLUSION: Stroke is an important cause of morbi-mortality in Asturias. The magnitude of mortality is larger than the expected from the incidence. It maybe explained by a high case/fatality ratio in Asturias due to proportion of hemorrhagic stroke, the ageing of the population and the distribution of competing causes of death. However, we cannot rule out a small incomplete registration of cases, mostly in patients over 85. We estimated the incidence of any stroke, given underegistration, to be 176/100,000 for any stroke.