The apnea hypopnea index is reported as the:

The apnea hypopnea index is reported as the:

• A. Percentage of sleep time demonstrating apnea and hypopneas
• B. Percentage of time sleep was disrupted by apnea and hypopneas per hour
• C. Average number of apneas and hypopneas that occurred during the night
• D. Average number of apneas and hypopneas seen per hour of sleep

Answer: (D)

AHI measures the average number of apneas and hypopneas per hour of sleep. This rate-normalized metric captures how often breathing pauses or shallow breaths occur during sleep, rather than what fraction of the night is affected or the total count across the night. So the correct definition is the average number of apneas and hypopneas seen per hour of sleep. It’s not a percentage of sleep time or a percentage of disrupted time, and it’s not simply the raw total for the night. Clinically, AHI is used to gauge severity by events per hour.

AHI measures the average number of apneas and hypopneas per hour of sleep. This rate-normalized metric captures how often breathing pauses or shallow breaths occur during sleep, rather than what fraction of the night is affected or the total count across the night. So the correct definition is the average number of apneas and hypopneas seen per hour of sleep. It’s not a percentage of sleep time or a percentage of disrupted time, and it’s not simply the raw total for the night. Clinically, AHI is used to gauge severity by events per hour.