Temporal trends in incidence and case fatality of intracerebral hemorrhage. The Tromsø Study 1995-2012
AuthorCarlsson, Maria; Wilsgaard, Tom; Johnsen, Stein Harald; Vangen-Lønne, Anne Merete; Løchen, Maja-Lisa; Njølstad, Inger; Mathiesen, Ellisiv B.
Background: The aim of this study was to explore temporal trends in incidence and case fatality rates of intracerebral hemorrhage (ICH) over the last two decades in a Norwegian municipality.
Methods: Incident cases of primary ICH were registered in the period from 1995 through 2012 in 32,530 par ticipants of the longitudinal population-based Tromsø Study. Poisson regression models were used to obtain incidence rates over time in age- and sex-adjusted and age- and sex-specific models. Case fatality rates were calculated and age- and sex-adjusted trends over time were estimated using logistic regression.
Results: A total of 226 ICHs were registered. The age- and sex-adjusted incidence rate [95% confidence interval (CI)] in the overall population was 0.42 (0.37–0.48) per 1,000 person-years. Age-adjusted incidence rates were 0.53 (0.43–0.62) in men and 0.33 (0.26–0.39) in women. In individuals aged <75 years, the age- and sex-adjusted incidence rate was 0.27 (0.22–0.32) and in individuals aged ≥75 years, it was 2.42 (1.95–2.89) per 1,000 person-years. There was no significant change in incidence rates over time. The incidence rate ratio (95% CI) in the overall population was 0.73 (0.47–1.12) in 2012 compared with 1995. The overall 30-day case fatality (95% CI) was 23.9% (18.3–29.5) and did not change substantially over time [odds ratio in 2012 vs. 1995 = 0.83 (95% CI 0.27–2.52)].
Conclusion: No significant changes in incidence and case fatality rates of ICH were observed during the last two decades.