Validation of the STOP questionnaire as a screening tool for OSA among different populations: a systematic review and meta-regression analysis Validation of the STOP questionnaire as a screening tool for OSA among different populations: a systematic review and meta-regression analysis Download Sleepy, tired, drowsy, and fatigue have different meanings for a university student sample Fraction of apnea is associated with the required continuous positive airway pressure level and reflects upper airway collapsibility in patients with obstructive sleep apnea