(278) Subarachnoid Hemorrhage Mortality Trends in U.S. Patients With Circulatory Disease (1999-2020)

Introduction: Subarachnoid hemorrhage is a neurological emergency that occurs as a result of bleeding into the subarachnoid space, with a mortality rate of approximately 44% and a worldwide annual occurrence estimated to be around 6.1 events per 100,000 individuals. Improved understanding of the determinants of ethnic variances and underlying comorbidities can assist primary prevention, which may lead to a reduced burden of subarachnoid hemorrhage within society, improve outcomes and lower healthcare costs.

Methods: Using the CDC multiple causes of death database (ICD-10 revision codes), we identified all patients who have circulatory system disease who died of subarachnoid hemorrhage (I60.x registered as the underlying cause of death) in two races (Caucasians and African Americans), between 1999 and 2020 in the United States. Age-adjusted mortality rates were calculated per 1,000,000 persons (PMP), standardized to the US census data from 1999, and stratified by race.

Results: Between 1999 and 2020, a total of 118,881 deaths were due to subarachnoid hemorrhage in patients with circulatory system disease identified in two races, with an overall age-adjusted mortality of 17.4 PMP. We identified a total of 17,770 deaths among African Americans, while 101,111 deaths in Caucasian populations. The overall age-adjusted mortality was 22.4 PMP in African Americans and, 16.7 PMP in Caucasians. Over the 21 years, the age-adjusted mortality decreased by 46 % in African Americans (from 33 PMP in 1999 to 17.7 PMP in 2020) and decreased by 34 % in Caucasians (from 22.2 PMP in 1999 to 14.6 PMP in 2020).

Conclusions: This study finds that between 1999 and 2020, African Americans have the highest rates of subarachnoid hemorrhage age-adjusted mortality among patients with circulatory system disease, whereas Caucasians have the lowest proportion despite having a 584% higher incidence rate in this ethnic subgroup. Interestingly, over the twenty-one years, mortality has decreased in both races.