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.