Of the 351 selected patients, 49 were excluded, 221 had OSA (apnea-hypopnea index ≥ 30) and they were randomized into NIV, CPAP, or control groups and 81 without OSA were randomized to NIV and control groups. Patients with and without OSA randomized to NIV and control were considered together. The resulting groups (NIV, CPAP, and control) were divided in patients treated with and without supplemental oxygen therapy to be compared. CPAP, continuous positive airway pressure; NIV, noninvasive ventilation; OSA, obstructive sleep apnea.