Excessive daytime sleepiness and mortality: Racial/ethnic variations in a large cohort of Veterans

Abstract: Study objectives: Disparities in access to care and healthcare system inequities result in race-based health care outcome differences. Excessive daytime sleepiness (EDS), as a general marker of health, is associated with all-cause mortality. We aimed to determine if the association and its effect size differ among various race and ethnic groups in a health care system with no or minimal race-based access limitation. Methods: We extracted Epworth Sleepiness Scale (ESS) of all Veterans with any sleep disorders for the years 1999–2022. ESS scores from 0 to 10 and 11–24 were categorized as normal and high, respectively. We further extracted the racial/ethnic groups as: White, Black, Hispanic, Native/Hawaiian, and Asian. We estimated unadjusted and adjusted odds ratios (OR and aOR) of all-cause mortality for those with high compared to normal ESS in various race/ethnicity groups. Adjusting factors included age, Body Mass Index (BMI), sex, and the Charlson Comorbidity Index (CCI). Results: 423,087 Veterans’ records showed at least one ESS value. The sample was overwhelmingly male (95 %), with mean age of 54.8 (±14.6), and mean BMI of 32.6 (±6.2). The aOR for all-cause mortality was 14 % higher (1.12–1.16) in the high-ESS category in the total sample. This association remained similar for White and Black individuals (aOR: 1.17, 95 % CI: 1.15–1.20 for White; aOR: 1.08, 95 % CI: 1.03–1.13 for Black population). There were no differences between normal and high ESS for other racial/ethnic groups. Conclusions: In this large real-life clinical cohort with a unique eligibility criterion, EDS link with increased all-cause mortality differed among various race/ethnic groups. In White and Blacks, EDS was associated with higher all-cause mortality. In contrast, EDS did not link with higher all-cause mortality in the other groups. Further research is needed to explore the biological reasons underpinning the study findings tying EDS to all-cause mortality.