Correlation of the Epworth Sleepiness Scale and Sleep-Disordered Breathing in Men and Women

To compare Epworth Sleepiness Scale (ESS) scores of men and women and determine if there is a correlation with sleep-disordered breathing (SDB) based on subsequent polysomnography (PSG).

Consecutive adult patients were identified who completed ESS and PSG at Mayo Clinic in Rochester, Minnesota, between January 1, 2013, and January 31, 2015. Apnea-hypopnea index (AHI) ≥ 5 events/h was classified as presence of SDB, and increasing values represented greater severity.

Among 6,593 patients with valid ESS scores and timely subsequent PSG, 42% were women. Mean (standard deviation [SD]) age of women was 56.2 (15.2) years; men, 58.5 (15.1) years. Mean (SD) ESS score was 9.5 (5.4) for women and 9.5 (5.3) for men. SDB was present in 83.6% of men and 68.3% of women. Mean (SD) AHI of men was 25.9 (26.7) events/h; women, 16.1 (22.4) events/h (P < .001). Each unit increase in ESS score of men was associated with a 0.51-unit increase in AHI (P < .001); women had a 0.16-unit associated increase (P = .04) (effect ratio, threefold greater for men). PSG demonstrated that women had greater sleep efficiency, less respiratory effort-related arousals, and less hypoxemia (all P < .001). Among women, ESS did not correlate with presence of SDB or mild to moderate SDB. There was a small association in women with severe SDB.

ESS is not correlated with SDB at mild to moderate levels in women and has a smaller association than in men with severe SDB. Further work is necessary to understand sex-specific differences in patients with SDB.