Abstract 145: Trends In The Incidence Of Spontaneous Subarachnoid Hemorrhages In The United States From 2006 To 2017

Abstract

Introduction: Global incidence of subarachnoid hemorrhage (SAH) is reportedly decreasing, but recent studies from the United States (US) are limited. The goal of this study is to evaluate trends in the incidence of SAH in different age, sex, and ethnic subgroups in the US over the last decade. Methods: We identified all new cases of spontaneous SAH from the 2006-2017 State Inpatient Databases in New York and Florida (n = 45,703) using validated International Classification of Diseases codes. Annual incidence was calculated by combining case counts with annual Census data. Joinpoint regression was used to trend incidence over time. Results: From 2006-2017, the mean age of SAH patients was 61.8 years and 59.3% were women. The proportion of smokers was 27.2% and this significantly increased over time (p<0.001). The annual age and sex-standardized incidence of SAH in cases per 100,000 ranged from 11.4-13.7, but women had a higher overall incidence (13.4-15.2) compared to men (9.2-12.1). When stratified by age groups, women(W) had a higher incidence of SAH compared to men (M) in similar age groups (age 20-44: W 4.7-5.7, M 3.3-4.4; age 45-64: W 16.2-18.2, M 11.0-14.7; age >=65: W 26.8-33.2, M 20.9-31.2). On Joinpoint regression, M >=65 yo had the highest annualized percentage change in incidence of 3.1% (95% CI 2.0-4.3). M 45-64 yo had an increase of 1.7% (95% CI 0.9-2.5) and W >=65 yo had an increase of 1.3% (95% CI 0.4-2.2). Incidence declined in W 20-44 yo by -1.0% per year while M 20-44 yo remained unchanged (Figure 1). On stratification by race, age and sex-standardized incidence was highest among African Americans (14.6-18.6 per 100,000), followed by Whites (10.0-11.9), Latino (8.0-11.3), and Asians (6.6-9.9). Conclusion: When compared to European studies, US residents have a higher incidence of spontaneous subarachnoid hemorrhage. The incidence of SAH is increasing in the older population and is highest among women and African Americans.