The Korean Obstructive Sleep Apnea Morbidity Study (KOSMOS) Protocol

Obstructive sleep apnea (OSA) is a heterogeneous syndrome with various predisposing factors, pathophysiological mechanisms, clinical presentations, and consequences of respiratory events. Treatment compliance and outcomes vary among the clinical subtypes of OSA. The best OSA treatment approach involves accurate clinical subtype diagnosis and long-term follow-up. However, most of the previous studies were conducted in Western populations, and few analyses of Korean data have been performed. To investigate the characteristics and long-term prognosis of Korean OSA patients, the Korean Obstructive Sleep apnea Morbidity Study (KOSMOS), a prospective large multicenter cohort, was designed. Adults diagnosed with OSA with an apnea-hypopnea index of ≥5 by type 1 polysomnography are enrolled regardless of subsequent positive airway pressure (PAP) treatment. Enrollment is possible through all departments treating patients with OSA. Follow-up will be performed every 12 months, and the study plans to follow the subjects for 30 years. Demographics, health behaviors, medical history, medication, family medical history, presence of snoring, and allergy will be investigated. Anthropometric measurements and blood pressure will be checked in the hospital. Polysomnography, PAP titration, and PAP compliance data will also be collected. Clinical questionnaires will be administered, and survival will be assessed. The KOSMOS cohort is the first and only prospective multicenter multidisciplinary OSA cohort study in Korea. Through this long-term planned cohort study, we will be able to gain a detailed understanding of the characteristics of OSA in Koreans and conduct a thorough analysis of the disease’s progression and prognosis.