The number of apneas and hypopneas recorded per hour of sleep during a sleep study. AHI is a clinical event-rate measure used in sleep-apnea assessment; a consumer wearable score or breathing flag is not an AHI.
The apnea–hypopnea index, or AHI, is calculated by dividing the total number of scored apneas and hypopneas by total sleep time in hours. An apnea is a period of absent airflow that meets defined clinical scoring criteria. A hypopnea is a qualifying reduction in airflow associated with oxygen desaturation or arousal under the applicable scoring rules. AHI is commonly used to describe the frequency and severity of sleep-disordered breathing, but it is not the complete meaning of a sleep study. Symptoms, oxygen burden, arousals, sleep position, sleep stages, cardiovascular context, and the distinction between obstructive and central events also matter. A consumer wearable may estimate oxygen, respiratory rate, movement, or respiratory irregularity. Those outputs are not interchangeable with AHI because the device does not reproduce the full clinical sensor set or event-scoring process. Sleepgenic never converts Garmin Breathing Disruption, SpO₂, awakenings, or sleep score into an inferred AHI. AHI belongs on the clinical side of the Clinical Signal Boundary. Wearable data may create a reason to consider evaluation; an appropriate sleep study produces the event-rate evidence.
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