Background: We determined the relationships among the subjective symptoms of sleep apnea and daytime sleepiness, depressive symptoms, and anxiety in adults with obstructive sleep apnea (OSA).

Methods: We developed the Subjective Apnea Severity Questionnaire (SASQ) to measure subjective OSA symptoms during the night and on waking in the morning. Construct validity and reliability were assessed. The Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and State Scale of State Trait Anxiety Inventory (STAI-S) were applied. Multiple linear regression analyses were performed, and the results were adjusted for several confounders.

Results: A total of 337 OSA patients were included. The SASQ consists of eight items with three domains. Cronbach's α for the SASQ was 0.657. The mean SASQ score was 1.35 ± 0.59. Symptoms related to nocturnal breathing difficulties were associated with polysomnographic (PSG) respiratory parameters. In the adjusted models, total SASQ scores were associated with ESS scores but not with BDI or STAI-S scores. Unlike other symptom groups, nocturnal breathing difficulties tended toward a positive relationship with ESS scores (p = 0.076), but were negatively related to BDI scores (p = 0.003) and STAI-S scores (p = 0.012). Symptoms related to nocturnal awakening or morning waking were either positively related or unrelated to ESS, BDI, and STAI-S scores.

Conclusions: The subjective OSA symptoms measured via the SASQ were associated with daytime sleepiness in adults with OSA, but not with depressive symptoms or anxiety. Nocturnal breathing difficulties were positively related to daytime sleepiness, but negatively related to depressive symptoms and anxiety.