Intracerebral hemorrhage mortality is not changing despite declining incidence

Abstract

Objective: To determine trends in incidence and mortality of intracerebral hemorrhage (ICH) in a rigorous population-based study.

Methods: We identified all cases of spontaneous ICH in a South Texas community from 2000 to 2010 using rigorous case ascertainment methods within the Brain Attack Surveillance in Corpus Christi Project. Yearly population counts were determined from the US Census, and deaths were determined from state and national databases. Age-, sex-, and ethnicity-adjusted incidence was estimated for each year with Poisson regression, and a linear trend over time was investigated. Trends in 30-day case fatality and long-term mortality (censored at 3 years) were estimated with log-binomial or Cox proportional hazards models adjusted for demographics, stroke severity, and comorbid disease.

Results: A total of 734 cases of ICH were included. The age-, sex-, and ethnicity-adjusted ICH annual incidence rate was 5.21 per 10,000 (95% confidence interval [CI] 4.36, 6.24) in 2000 and 4.30 per 10,000 (95% CI 3.21, 5.76) in 2010. The estimated 10-year change in demographic-adjusted ICH annual incidence rate was -31% (95% CI -47%, -11%). Yearly demographic-adjusted 30-day case fatality ranged from 28.3% (95% CI 19.9%, 40.3%) in 2006 to 46.5% (95% CI 35.5, 60.8) in 2008. There was no change in ICH case fatality or long-term mortality over time.

Conclusions: ICH incidence decreased over the past decade, but case fatality and long-term mortality were unchanged. This suggests that primary prevention efforts may be improving over time, but more work is needed to improve ICH treatment and reduce the risk of death.

Figure 1. Trend in adjusted intracerebral hemorrhage incidence rate

Points represent the model-predicted incidence treating year as a categorical variable. Smoothed lines represent the model-predicted incidence assuming a linear trend. (A) Overall age-, sex-, and ethnicity-adjusted rates for all individuals 45 and older. (B) Sex- and ethnicity-adjusted rates by age group.

Figure 2. Trend in adjusted intracerebral hemorrhage 30-day case fatality

Points represent the model-predicted mortality treating year as a categorical variable. Smoothed lines represent the model-predicted mortality assuming a linear trend with time. (A) Adjusted for age (quadratic due to nonlinear effects), sex, and ethnicity. (B) Additionally adjusted for NIH Stroke Scale (quadratic due to nonlinear effects), Glasgow Coma Scale, coronary disease, prior stroke/TIA, atrial fibrillation, diabetes, and smoking.