Case-fatality rates and functional outcome after subarachnoid hemorrhage: a systematic review.

BACKGROUND: During the last three decades, new management strategies have been developed for patients with aneurysmal subarachnoid hemorrhage. To assess whether the case-fatality rate has improved after the introduction of new management strategies, we studied outcome in all population-based studies from 1960 onward. SUMMARY OF REVIEW: To identify population-based studies that reported on case-fatality rate in subarachnoid hemorrhage, we performed a MEDLINE search and checked all reference lists of the studies found. Two authors (J.W.H. and G.J.E.R.) independently assessed all studies for eligibility, using predefined criteria for case finding and diagnosis, and extracted data on case-fatality rates. We used weighted linear regression analysis to quantify change in case-fatality rate over time. We found 21 studies, describing 25 study periods between 1960 and 1992. Case-fatality rates varied between 32% and 67%, with the exception of one recent study. The case-fatality rate decreased by 0.5% per year (95% confidence interval, -0.1 to 1.2); the decline was steeper after adjustment for age and sex (0.9% per year; 95% confidence interval, -0.7 to 2.6; data from 12 studies).
CONCLUSIONS: The case-fatality rate after subarachnoid hemorrhage has decreased during the last three decades. A plausible explanation for this decrease is the improved management of patients with subarachnoid hemorrhage.