Epidemiology and trends in stroke mortality in the USA, 1975-2019

Background: Whether changes in stroke mortality are affected by age distribution and birth cohorts, and if the decline in stroke mortality exhibits heterogeneity by stroke type, remains uncertain.

Methods: We undertook a sequential time series analysis to examine stroke mortality trends in the USA among people aged 18-84 years between 1975 and 2019 (n = 4 332 220). Trends were examined for overall stroke and by ischaemic and haemorrhagic subtypes. Mortality data were extracted from the US death files, and age-sex population data were extracted from US census. Age-standardized stroke mortality rates and incidence rate ratio (IRR) with 95% confidence interval [CI] were derived from Poisson regression models.

Results: Age-standardized stroke mortality declined for females from 87.5 in 1975 to 30.9 per 100 000 in 2019 (IRR 0.27, 95% CI 0.26, 0.27; average annual decline -2.78%, 95% CI -2.79, -2.78). Among males, age-standardized mortality rate declined from 112.1 in 1975 to 38.7 per 100 000 in 2019 (RR 0.26, 95% CI 0.26, 0.27; average annual decline -2.80%, 95% CI -2.81, -2.79). Stroke mortality increased sharply with advancing age. Decline in stroke mortality was steeper for ischaemic than haemorrhagic strokes.

Conclusions: Stroke mortality rates have substantially declined, more so for ischaemic than haemorrhagic strokes.