Definition of Obstructive Sleep Apnea Syndrome (OSAS), Obstructive Apnea-Hypopnea Index (OAHI), and Oxygen Desaturation Index (ODI)

OAHI and ODI were calculated based on the American Academy of Sleep Medicine pediatric criteria.¹³ Respiratory event types (obstructive, mixed, hypopneas, central) were summarized as indices (the number of respiratory events divided by the hours of total sleep time). The OAHI was then defined as the sum of all obstructive and mixed apneas, plus hypopneas associated with a 50% reduction in airflow and either at least 3% desaturation or electroencephalographic arousal, divided by hours of total sleep time. The ODI was defined as the number of at least 3% desaturation from baseline saturation per hour of sleep.