Introduction: High-quality epidemiological data on hemorrhagic stroke (HS) and its subtypes, intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), remains limited in Asian ethnicities. We investigated the trends in HS incidence and 30-day mortality from 2005 to 2019 in a multi-ethnic Asian population from a national registry.
Patients and methods: Data on all stroke cases from the Singapore Stroke Registry from 2005 to 2019 were collected. Cases were defined using centrally adjudicated review of diagnosis codes. Death outcomes were obtained by linkage with the national death registry. Incidence (per 100,000 people) and 30-day mortality (per 100 people) were measured as crude and age-standardized rates. Trends were analyzed using linear regression.
Results: We analyzed 19,017 cases of HS (83.9% ICH; 16.1% SAH). From 2005 to 2019, age-standardized incidence rates (ASIR) for HS remained stable from 34.4 to 34.5. However, age-standardized mortality rates (ASMR) decreased significantly from 29.5 to 21.4 (p < 0.001). For ICH, ASIR remained stable while ASMR decreased from 30.4 to 21.3 (p < 0.001); for SAH, ASIR increased from 2.7 to 6.0 (p = 0.006) while ASMR remained stable. In subgroup analyses, HS incidence increased significantly in persons <65 years (from 18.1 to 19.6) and Malays (from 39.5 to 49.7).
Discussion: From 2005 to 2019, ASIR of HS remained stable while ASMR decreased. Decreasing ASMR reflects improvements in the overall management of HS, consistent with global trends.
Conclusion: Population health efforts to address modifiable risk factors for HS in specific demographic subgroups may be warranted to reduce incidence and mortality of HS.
Keywords: Hemorrhagic stroke; epidemiology; incidence; intracerebral hemorrhage; mortality; subarachnoid hemorrhage.