Excessive daytime sleepiness and mortality: racial/ethnic variations in a large cohort of veterans

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.

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).

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.

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.