Incidence, recurrence and prevalence of stroke in an ageing population

Abstract

Background Populations are ageing and survival from many diseases including stroke has improved substantially over the past decades. Even if stroke incidence is declining as well, at least in the population 65 years and above, there is concern that the burden of stroke will increase in the coming decades, when the population grow larger and older. However, few studies have explored how incidence, recurrence and prevalence have developed in parallel with population ageing. It needs to be further investigated whether or not the decline in incidence is large enough to compensate for the ageing of the population, and, how the incidence of recurrent stroke has developed when survival from the first stroke has improved, before we can make any clear statements of the future burden of stroke. Aim and setting In this population-based study based on Swedish register data we explore how the rate of recurrent events of stroke has developed in relation to the rate of first events. Further, how the prevalence of stroke has developed when survival has improved and the population has become older, and, finally, how the absolute number of stroke events developed. Trends are estimated for the period 1994 to 2014. Based on the findings, we discuss the future disease burden of stroke. Results We found clear declines in both incidence of first as well as recurrent stroke in Sweden between 1994 and 2014 for all ages between 60 and up to 90. For ages above 90 years the trends have remained stable. Despite improved survival of stroke the prevalence has not increased but decreased during the period, both as a proportion and as absolute number of events. Conclusion Based on the development the past 15 years in Sweden in the population 65 and older we do not find support for an increasing burden of stroke, despite an ageing population.