Diagnostic Thresholds for Sleep Apnea

Apnea-Hypopnea Index (AHI) Thresholds

The American Academy of Sleep Medicine recommends an AHI of less than 5 events per hour as normal, while an AHI of 5-14 events/hour indicates mild OSA, 15-29 events/hour indicates moderate OSA, and ≥30 events/hour indicates severe OSA 1, 2, 3
An AHI ≥15/hour in REM sleep is considered moderate to severe OSA by the American Academy of Sleep Medicine 4
Alternative thresholds use AHI ≥10 events/hour as the cutoff for OSA diagnosis, though the AHI ≥5 threshold is more widely accepted in current practice 1, 2, 3

The definition of hypopnea significantly impacts AHI calculation, with the American Academy of Sleep Medicine defining hypopnea as a ≥30% reduction in airflow for ≥10 seconds associated with either ≥3% oxygen desaturation or an arousal 8
The American Academy of Sleep Medicine specifically indicates that AHI values ≥15/hour in REM sleep are considered moderate to severe 4