STUDY OBJECTIVES:Few population-based studies have explored how excessive sleepiness (ES) contributes to burden of illness among patients with obstructive sleep apnea (OSA). METHODS:This study utilized data from the annual, cross-sectional 2016 US National Health and Wellness Survey. Respondents self-reporting an OSA diagnosis were categorized as having ES (Epworth Sleepiness Scale [ESS] score ≥ 11) or not having ES (ESS score < 11). Comorbidities, health-related quality of life (HRQoL), and productivity were examined in three groups: OSA with ES (n = 731), OSA without ES (n = 1,452), and non-OSA controls (n = 86,961). RESULTS:The OSA with ES group had significantly higher proportions of respondents reporting depression (62.4% versus 48.0%), gastroesophageal reflux disease (39.0% versus 29.4%), asthma (26.3% versus 20.7%), and angina (7.8% versus 6.7%) compared to the OSA without ES group (P < .05). After controlling for covariates, the OSA with ES group had significantly lower (worse) scores for mental component score (41.81 versus 45.65 versus 47.81), physical component score (46.62 versus 48.68 versus 51.36), and SF-6D (0.65 versus 0.69 versus 0.73) compared with OSA without ES and non-OSA controls (all P < .001). The OSA with ES group had significantly higher (greater burden) mean rates of presenteeism (25.98% impairment versus 19.24% versus 14.75%), work impairment (29.41% versus 21.82% versus 16.85%), and activity impairment (31.09% versus 25.46% versus 19.93%) compared with OSA without ES and non-OSA controls (all P < .01) after controlling for covariates. CONCLUSIONS:OSA with ES is associated with higher prevalence of comorbidities, reduced HRQoL, and greater impairment in productivity compared to OSA without ES and compared to non-OSA controls.