Key result
Between 1994 and 2014, the incidence rates of both first and recurrent strokes declined in Sweden across all ages up to 90 years, leading to a decrease in the prevalence proportion of stroke to around 3% in 2014.
Why the study?
It was uncertain whether an ageing population and improved survival would increase stroke prevalence, recurrent stroke incidence rates, or absolute numbers of strokes.
Observational
Decreasing incidence rates of stroke have successfully offset the expected increase in absolute and relative numbers of stroke that would have otherwise occurred due to an ageing population and improved survival.
Answers are grounded in this paper and cite their sources.
Declining stroke incidence may reflect better prevention in older adults; leaves open generalizability beyond Sweden and causal drivers.
BACKGROUND: Stroke incidence has declined during the past decades. Yet, there is a concern that an ageing population together with improved survival after stroke will result in a raised proportion of the population who have experienced a stroke, as well as increasing incidence rate of recurrent strokes, and, absolute numbers of strokes. The objectives of this study were to investigate how the age specific incidence rates of recurrent strokes have developed in relation to the incidence rates of first strokes and how the postponement in age look like, and to see how the prevalence proportion of stroke as well as the absolute number of incident strokes has changed over time. METHODS: This study includes the total Swedish population born 1890-1954 living in Sweden from 1987. Stroke was identified through hospital admissions and deaths in national health registers (mandatory for all hospitals in Sweden). Age specific incidence rates were calculated for first, second, all recurrent, and all strokes for each calendar year between 1994 and 2014 for each age between 60 and 104 years. The proportion in the population with a history of stroke up to 7 years back in time was also calculated for different age groups and for different calendar years. RESULTS: Not only the incidence rate of first stroke but also of recurrent strokes have declined. The declines are evident in all ages up to 90 years of age, but not in ages above 90 years. Despite improved survival in stroke, the prevalence proportion has declined over the period and was around 3% in 2014 (somewhat higher for men than women). Even incident cases of stroke in absolute number has declined. CONCLUSIONS: Decreasing incidence rates of stroke have offset an increase in both absolute and relative numbers of stroke that otherwise would have taken place due to improved survival and an ageing population. The decline in stroke recurrence has been as strong as the decline in first strokes.
No takes yet. Share an insight, caveat, or question.
Modig et al. (2019) conducted an observational in Stroke. Calendar year (1994-2014) vs. Earlier calendar years was evaluated on Age-specific incidence rates of first and recurrent strokes, and prevalence proportion of stroke. Between 1994 and 2014, the incidence rates of both first and recurrent strokes declined in Sweden across all ages up to 90 years, leading to a decrease in the prevalence proportion of stroke to around 3% in 2014.
Synapse has enriched 10 related papers. Consider them for comparative context: