Declining first-ever stroke incidence rates in 15- to 54-year-old residents of Tartu, Estonia, from 1991 to 2017

Abstract

Background: Having a stroke at a young age has a huge socioeconomic impact. Data on the trends of stroke incidence in young adults from prospective population-based studies are scarce. Aims: The aim of this study was to analyze the trends in stroke incidence in 15- to 54-year-old residents of Tartu, Estonia from 1991 to 2017. Methods: Three population-based studies with identical study protocols determining the incidence of first-ever stroke have previously been conducted in Tartu, Estonia (1991–1993, 2001–2003, and 2013–2017). All residents of Tartu with first-ever stroke (ischemic stroke, spontaneous intracerebral hemorrhage, and subarachnoid hemorrhage) who were hospitalized to the Department of Neurology, Tartu University Hospital in respective study periods were included prospectively. Overlapping data sources for case ascertainment were used to include both hospitalized and non-hospitalized cases. Trends in first-ever stroke incidence in 15- to 54-year-old residents of Tartu were calculated and compared using rate ratio (RR). Results: Altogether 259 strokes were identified. From 1991 to 2017, the proportion of women increased from 38.3% to 43.6%. Mean age at onset in women decreased from 46.9 (standard deviation (SD): 7.3) to 42.6 (SD: 8.9). Overall crude incidence rates per 100,000 decreased significantly from 1991 to 2003 (from 57.2 (95% confidence interval (CI): 46.9–69.1) to 35.7 (95% CI: 25.7–48.3)); RR: 0.62 (95% CI: 0.44–0.89). While also present in women, the decrease was most notable in 45- to 54-year-old men (RR: 0.55 (95% CI: 0.30–0.99)). In 35- to 44-year-old men, the incidence rates decreased significantly from 2001 to 2017 (RR: 0.37 (95% CI: 0.14–0.99)). Conclusion: The overall first-ever stroke incidence rates decreased from 1991 to 2003 and remained stable thereafter.