Trends in incidence and in short term survival following a subarachnoid haemorrhage in Scotland, 1986 - 2005: a retrospective cohort study
1 NHS Quality Improvement Scotland, Glasgow G1 2NP, UK
2 Department of Public Health, University of Glasgow, Glasgow, UK
3 British Heart Foundation, Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
4 ISD, Edinburgh, UK
5 Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
6 Department of Public Health, University of Liverpool, UK
BMC Neurology 2011, 11:38 doi:10.1186/1471-2377-11-38Published: 29 March 2011
To examine age and sex specific incidence and 30 day case fatality for subarachnoid haemorrhage (SAH) in Scotland over a 20 year period.
A retrospective cohort study using routine hospital discharge data linked to death records.
Between 1986 and 2005, 12,056 individuals experienced an incident SAH. Of these 10,113 (84%) survived to reach hospital. Overall age-standardised incidence rates were greater in women than men and remained relatively stable over the study period. In 2005, incidence in women was 12.8 (95% CI 11.5 to 14.2) and in men 7.9 (95% CI 6.9 to 9.1). 30 day case fatality in individuals hospitalised with SAH declined substantially, falling from 30.0% in men and 33.9% in women in 1986-1990 to 24.5% in men and 29.1% in women in 2001-2005. For both men and women, the largest reductions were observed in those aged between 40 to 59 years. After adjustment for age, socio-economic status and co-morbidity, the odds of death at 30 days in 2005 compared to odds of death in 1986 was 0.64 (0.54 to 0.76), p < 0.001 for those below 70 years, and 1.14 (0.83 to 1.56), p = 0.4 in those 70 years and above.
Incidence rates for SAH remained stable between 1986 and 2005 suggesting that a better understanding of SAH risk factors and their reduction is needed. 30 day case fatality rates have declined substantially, particularly in middle-age. However, they remain high and it is important to ensure that this is not due to under-diagnosis or under-treatment.