Stable incidence but declining case-fatality rates of subarachnoid hemorrhage in a population

Abstract

Objective: To characterize temporal trends in subarachnoid hemorrhage (SAH) incidence and outcomes over 5 time periods in a large population-based stroke study in the United States.Methods: All SAHs among residents of the Greater Cincinnati/Northern Kentucky region at least 20 years of age were identified and verified via study physician review in 5 distinct year-long study periods between 1988 and 2010. We abstracted demographics, care patterns, and outcomes, and we compared incidence and case-fatality rates across the study periods.Results: The incidence of SAH in the 5 study periods (age-, race-, and sex-adjusted to the 2000 US population) was 8.8 (95% confidence interval 6.8-10.7), 9.2 (7.2-11.2), 10.0 (8.0-12.0), 9.0 (7.1-10.9), and 7.7 (6.0-9.4) per 100,000, respectively; the trend in incidence rates from 1988 to 2010 was not statistically significant (p 5 0.22). Advanced neurovascular imaging, endovascular coiling, and neurologic intensive care unit availability increased significantly over time. All-cause 5-day (32%-18%, p 5 0.01; for trend), 30-day (46%-25%, p 5 0.001), and 90-day (49%-29%, p 5 0.001) case-fatality rates declined from 1988 to 2010. When we included only proven or highly likely aneurysmal SAH, the declines in case-fatality were no longer statistically significant. Conclusions:Although the incidence of SAH remained stable in this population-based region, 5-day, 30-day, and 90-day case-fatality rates declined significantly. Advances in surgical and medical management, along with systems-based changes such as the emergence of neurocritical care units, are potential explanations for the reduced case-fatality.

Population-based stroke surveillance using Big Data: epidemiological trends in admissions and mortality in Australia

“…Our finding of unchanged risk of subarachnoid haemorrhage and declining mortality corroborates other findings. 36 This analysis updates our earlier data linkage study reporting decreasing mortality for intracerebral 12 and subarachnoid haemorrhage in NSW from 2001 to 2009, 13 demonstrating sustained mortality reductions for these sub-types with more recent data.…”

“…Several studies have demonstrated recent declines in stroke rates and mortality, although this experience is not universal. [30][31][32][33][34][35][36][37][38][39] Two studies utilising administrative data from England 30 and Sweden 31 While neither study included subarachnoid haemorrhage nor reported statistics separately for intracerebral and ischaemic stroke, both reported reductions in stroke incidence and mortality. Our finding of unchanged risk of subarachnoid haemorrhage and declining mortality corroborates other findings.…”

Decreasing Risk of Fatal Subarachnoid Hemorrhage and Other Epidemiological Trends in the Era of Coiling Implementation in Australia

“…In contrast, recent evidence for declining mortality is sparse. Two recent publications demonstrate declines in the USA ( 24 ) and England ( 25 ) for periods to 2010 and another two publications one each from the USA and UK for periods to 2008 ( 22 , 26 ), while in-hospital mortality significantly declined from 2000 to 2015 in those select SAH patients requiring intensive care in Australia and New Zealand ( 27 ). Declines in fatal SAH rates were not apparent in those aged over 70 years, suggesting that their exposure to risk factors has not altered over time.…”

Incidence and outcome of subarachnoid haemorrhage in the general and emergency department populations in Queensland from 2010 to 2014

“…Cigarette smoking and hypertension are notable risk factors . Mortality is higher with older age and appears to be decreasing …”

“…[8][9][10][11] Mortality is higher with older age and appears to be decreasing. 12,13 The crude incidence of SAH in Australia is estimated to be 10.3 (95% CI 10.1-10.4) per 100 000 person-years. 14 In that study, patients admitted to hospitals between 1998 and 2008 were identified in the National Hospital Morbidity Database.…”