Supplementary Material for: Long-term trends in incidence, attack rates, and early case-fatality of spontaneous intracerebral hemorrhage. Dijon Stroke Registry (1985-2022)

Background: Spontaneous intracerebral hemorrhage (ICH) is a leading cause of disability and death worldwide. Understanding temporal trends in the burden of the disease is critical to evaluate the effectiveness of preventive strategies and identify targets for action. This study aimed to assess long-term temporal trends in incidence, attack rates, and early case-fatality of ICH. Methods: All cases of ICH among residents of Dijon, France, were prospectively recorded between 1985 and 2022 using a population-based registry. Annual incidence and attack rates were assessed, and temporal trends were analysed by calculating incidence (IRR) and attack rate ratios (ARR). Case-fatality was measured at 30 days. Results: 1,015 ICH cases (mean age 73.5 ±16.4 years old, 52.7% women) were recorded including 815 patients with a first-ever ICH and 200 cases of ICH as stroke recurrences. Age-standardized incidence increased progressively from 12.6/100,000/year in 1985-1991 to 20.8/100,000/year in 2011-2016 (IRR: 1.96, p<0.001). A slight decrease was observed during period 2017-2022 (18.9/100,000/year, IRR: 0.81; 95% CI: 0.61-1.06, p=0.11). A similar trend was noted in attack rates, with a peak during 2011-2016 (27.9/100,000/year; ARR: 1.79 95% CI: 1.47-2.20, p<0.001) and a decrease in the most recent period (23.2/100,000/year; ARR: 0.83; 95% CI: 0.69-0.99, p=0.04). In men, a significant increase in incidence and attack rates was observed from 1985-1991 to 2011-2016, followed by a slight decline. In contrast, women showed a delayed increase in rates, with no decline in the most recent period. The 30-day case-fatality rate declined between 1985 and 2010 (from 40.3% to 26.3%), followed by an increase thereafter, reaching 38.8% during the last study period Conclusion: Our study revealed an overall increase in incidence and attack rates of ICH followed by a slight decline in recent years. Sex-differences in trends warrant further investigation into the contributing factors, and emphasizes the continued need for prevention strategies to further reduce the burden of ICH. The recent increase in early case-fatality rates highlights the need for specific acute-phase treatments of ICH.