Declining Rates of Fatal and Nonfatal Intracerebral Hemorrhage: Epidemiological Trends in Australia

Abstract

Background A recent systematic review of epidemiological studies reported intracerebral hemorrhage ( ICH ) incidence and mortality as unchanged over time; however, comparisons between studies conducted in different health services obscure assessment of trends. We explored trends in ICH rates in a large, representative population in New South Wales, Australia's most populous state (≈7.3 million). Methods and Results Adult hospitalizations with a principal ICH diagnosis from 2001 to 2009 were linked to death registrations through to June 30, 2010. Trends for overall, fatal, and nonfatal ICH rates within 30 days and fatal rates for 30‐day survivors at 365 days were calculated. There were 11 332 ICH patient admissions meeting eligibility criteria, yielding a crude hospitalization rate of 25.2 per 100 000 (age‐standardized rate: 17.2). Age‐ and sex‐adjusted overall rates significantly declined by an average of 1.6% per year ( P =0.03). Fatal ICH declined by an average of 2.6% per year ( P =0.004). For 30‐day survivors, a nonsignificant decline of 2.3% per year in fatal ICH at 365 days was estimated ( P =0.17). Male sex and birth in the Oceania region and Asia were associated with an increased ICH risk, although this depended on age. Approximately 12% of ICH admissions would be prevented if the socioeconomic circumstances of the population equated with those of the least disadvantaged. Conclusions Overall and fatal ICH rates have fallen in this large Australian population. Improvements in cardiovascular prevention and acute care may explain declining rates. There was no evidence of an increase in devastated survivors because the longer term mortality of 30‐day survivors has not increased over time.