definition of ahi
Each episode must last at least 10 sec. The AHI is one indicator of obstructive sleep apnea, although it is recognized as an imperfect diagnostic tool. An AHI of 30 or more events in an hour indicates severe sleep apnea; 15 to 29 events suggests moderate apnea; and 5 to 14 events indicates mild apnea.
The AHI is calculated by dividing the number of apnea events by the number of hours of sleep. The AHI values are categorized as: 1  Normal: 0-4. 2  Mild sleep apnea: 5-14. 3  Moderate sleep apnea: 15-29.