Incidence of Stroke Subtypes, Prognosis and Prevalence of Risk Factors in Joinville, Brazil: A Two-Year, Community- Based Study

Abstract

Background: There have been few population-based studies on stroke risk factors and prognosis conducted in Brazil. The objective of this study was to evaluate, over a two year period, the incidence of the subtypes of first-ever strokes, the prevalence of cardiovascular risk factors and functional prognosis in a city located in the south of Brazil.

Methods: The period from January of 2005 to December of 2006 was evaluated prospectively by compiling data on first-ever stroke cases, medications used prior to the morbidity and the incidence of traditional risk factors. The annual incidence was adjusted for age using the direct method. Patients were monitored for at least 6 months following the event.

Results: Of 1323 stroke cases, 759 were first-ever stroke cases. Of those, 610 were classified as infarctions, 94 as intra-cerebral hemorrhages and 55 as subarachnoid hemorrhages. The crude incidence rate per 100 000 inhabitants was 61.8 for infarction (95% CI, 57.0-66.9), 9.5 for intra-cerebral hemorrhage (95% CI, 7.7-11.6) and 5.6 for subarachnoid hemorrhage (95% CI, 4.2-7.3).The 30 day case-fatality was 19.1%. The most prevalent cardiovascular risk factor was arterial hypertension. By post-stroke month 6, 25% had died (95% CI, 21.4-29.1), whereas 61.5% had regained their independence (95% CI, 56.2-68.3).

Conclusions: Case-fatality rate, prognosis and incidence adjusted for stroke subtypes were similar to those found in other population-based studies. The prevalence rates of ischemic heart disease, dyslipidemia, arterial hypertension and diabetes suggest that Joinville presents a mixed pattern of cardiovascular risk, a pattern seen in developed and developing countries alike.

Key words: stroke ; epidemiology ; incidence ; prognosis ; risk factors.