To evaluate trends in short- and long-term case-fatality after acute stroke in Ontario, Canada from 2003-2018.

Stroke mortality is decreasing in developed countries, but the extent to which this is due to decreasing incidence compared with decreasing case-fatality rate is not clear.

We included all patients over 18 years of age discharged from acute care or seen in the emergency department with first acute ischemic stroke or intracranial hemorrhage in Ontario, Canada from April 2003 to March 2018.  Crude and age-/sex- standardized case-fatality was evaluated at 30-days and 1-year.  We used the Cochran-Armitage test to evaluate changes in crude case-fatality across the study period.

Our cohort included 168,119 patients with acute stroke, 87.3% of which had ischemic stroke. In the study period, there was a rising proportion of young individuals (age <60; 14.9% in 2003 to 17.8% in 2018) and women (49.5% to 50.7%).  Thirty-day crude case-fatality rates decreased significantly among all strokes (20.2% to 12.6%), ischemic stroke (16.5% to 10.2%), and intracranial hemorrhage (44.5% to 29.8%).  One-year case-fatality also decreased among all strokes (32.2% to 22.4%), ischemic stroke (28.9% to 20.0%), and intracranial hemorrhage (54.5% to 39.3%; all p<.001).  Downward trends were apparent even in the most recent 5 years and persisted after age and sex standardization.

We show a prominent reduction in both short- and long-term acute stroke case-fatality from 2003-2018, particularly for intracranial hemorrhage.  Future research should determine the factors most likely to account for the reduction in case-fatality, in order to further optimize acute stroke care.