Remarkable decline in ischemic stroke mortality is not matched by changes in incidence

Abstract

Background and purpose: In Western Europe, mortality from ischemic stroke (IS) has declined over several decades. Age-sex-specific IS mortality, IS incidence, 30-day case fatality, and 1-year mortality after hospital admission are essential for explaining recent trends in IS mortality in the new millennium.

Methods: Data for all IS deaths (1980-2010) in the Netherlands were grouped by year, sex, and age. A joinpoint regression was fitted to detect points in time at which significant changes in the trends occur. By linking nationwide registers, a cohort of patients first admitted for IS between 1997 and 2005 was constructed and age-sex-specific 30-day case fatality and 1-year mortality were computed. IS incidence (admitted IS patients and out-of-hospital IS deaths) was computed by age and sex. Mann-Kendall tests were used for trend evaluation.

Results: IS mortality declined continuously between 1980 and 2000 with an attenuation of decline in the 1990s in some of the age-sex groups. A remarkable decline in IS mortality after 2000 was observed in all age-sex groups, except for young men. An improved decline in 30-day case fatality and in 1-year mortality was also observed in almost all age-sex groups. In contrast, IS incidence remained stable between 1997 and 2005 or even increased slightly.

Conclusions: The recent remarkable decline in IS mortality was not matched by a decline in the number of incident nonfatal IS events. This is worrying, because IS is already a leading cause of adult disability, claiming a heavy human and economic burden. Prevention of IS is therefore now of the greatest importance.