RESUMO
BACKGROUND AND PURPOSE: This study describes the large variations in outcome after stroke between countries that participated in the International Stroke Trial and seeks to define whether they could be explained by variations in case mix or by other factors. METHODS: We analyzed data from the 15 116 patients recruited in Argentina, Australia, Italy, the Netherlands, Norway, Poland, Sweden, Switzerland, and the United Kingdom: We compared crude case fatality and the proportion of patients dead or dependent at 6 months; we used logistic regression to adjust for age, sex, atrial fibrillation, systolic blood pressure, level of consciousness, and number of neurological deficits. We used the frequency of prerandomization head CT scan and prescription of aspirin at discharge to indicate quality of care. RESULTS: The differences in outcome (all treatment groups combined) between the "best" and "worst" countries were very large for death (171 cases per 1000 patients) and for death or dependency (375 cases per 1000 patients). The differences were somewhat smaller after adjustment for case mix (160 and 311 cases per 1000 patients, respectively). Process of care may have accounted for some but not all of the residual variation in outcome. CONCLUSIONS: Adjustment for case mix explained only some of the variation in outcome between countries. The residual differences in outcome were too large to be explained by variations in care and most likely reflect differences in unmeasured baseline factors. These findings demonstrate the need to achieve balance of treatment and control within each country in multinational randomized controlled stroke trials and the need for caution in the interpretation of nonrandomized comparisons of outcome after stroke between countries.
Assuntos
Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Acidente Vascular Cerebral/mortalidade , Idoso , Argentina/epidemiologia , Aspirina/uso terapêutico , Austrália/epidemiologia , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Heparina/uso terapêutico , Humanos , Modelos Logísticos , Masculino , Modelos Estatísticos , Avaliação de Resultados em Cuidados de Saúde/tendências , Polônia/epidemiologia , Valor Preditivo dos Testes , Avaliação de Processos em Cuidados de Saúde/estatística & dados numéricos , Avaliação de Processos em Cuidados de Saúde/tendências , Prognóstico , Qualidade da Assistência à Saúde , Curva ROC , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/tratamento farmacológico , Taxa de Sobrevida/tendências , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Comparing stroke rates in different parts of the world and at different points in time may increase our understanding of the disease. Comparisons are only meaningful if they are based on studies that use similar definitions, methods, and data presentation. SUMMARY OF REVIEW: We discuss the criteria that make such studies comparable, drawing on the experiences of recent studies performed around the world. If only those studies that fulfill the proposed criteria for comparison are considered, comparable data do not exist for vast areas of the world, including Africa, Asia, and South America. The importance of complete, community-based case ascertainment, including strokes managed outside the hospital, is emphasized. An approach for measuring and comparing the incidence of the pathological types of stroke (cerebral infarction, primary intracerebral hemorrhage, and subarachnoid hemorrhage) and subtypes of cerebral infarction is suggested. CONCLUSIONS: The "ideal" stroke incidence study does not exist, but studies closely approaching it will reveal the most reliable and comparable results. There is a need for further studies to fill the gaps in our knowledge of the worldwide incidence of stroke, particularly for developing countries.