What is the estimated incidence of aSAH in the United States?
Estimates of the incidence of aSAH in the United States vary, but the 2003 Nationwide Inpatient Sample provided an annual estimate of 14.5 discharges for aSAH per 100 000 adults.7 Because death resulting from aSAH often occurs before hospital admission (an estimated 12% to 15% of cases),8,9 the true incidence of aSAH might be even higher.