Factors associated with improvements in subjective symptoms of obstructive sleep apnea syndrome after continuous positive airway pressure therapy.

Purpose: Continuous positive airway pressure (CPAP) therapy improves subjective symptoms in obstructive sleep apnea syndrome (OSAS) patients; however, factors predicting symptom improvement post-CPAP therapy and the CPAP duration necessary for improving subjective symptoms are unclear. This study aimed to identify these factors and the appropriate nightly CPAP duration for improving subjective symptoms.

Methods: We recruited 359 subjects who completed both overnight polysomnography and subjective symptom assessments using the Epworth Sleepiness Scale (ESS), Zung Self-Depression Scale (SDS), and Pittsburgh Sleep Quality Index (PSQI).