Temporal trends and clinical characteristics of spontaneous intracerebral haemorrhage in the Waikato region of New Zealand: a hospital-based analysis.

Aims: To determine the incidence, and any change in incidence, of spontaneous intracerebral haemorrhage (ICH) detected in the hospitals of the Waikato region of New Zealand (NZ) between 1999 and 2008. To analyse clinical and patient parameters, and to correlate these with outcome.

Methods: A retrospective analysis was performed on patients presenting to Waikato and Thames Hospitals with ICH during the study period. Radiology reports, blood tests and the electronic clinical record were reviewed for each patient.

Results: 653 episodes of ICH were identified. The average annual incidence per 100,000 per year was 17.4 (16.1-18.7, 95% confidence interval). This increased from an average of 14.4 (13.7-15.1) between 1999-2001 to 21.4 (20.6-22.2) between 2006-2008 (rate ratio 1.49, p<0.0001). 249 (38.1%) patients died within 30 days of their sentinel bleed. The presence of intraventricular extension of bleed on neuroimaging (Odds Ratio (OR) 6.18, p<0.001), warfarin use (OR 1.11, p=0.76), warfarin use and intraventricular extension of bleed (OR 23.8, p=0.014), lobar location of bleed (OR 1.88, p=0.001) and age (OR 1.16 for every 10-year increase in age, p=0.02) increased the likelihood of death within 30 days.

Conclusion: Observed ICH has increased in incidence in our hospitals over the past 10 years. Increasing availability of neuroimaging, increasing numbers of elderly, and increasing warfarin associated ICH were likely contributors to this observed increase. Radiological evidence of extension of intraventricular bleed, warfarin use, lobar location of bleed, and increasing age correlated with poorer survival. This data will be available for comparison with future studies to assess trends in incidence, patient characteristics and outcome in ICH.