Coding Cues: How to measure sleep to establish coverage for CPAP therapy

July 4, 2008

We're confused by the time requirements to establish the AHI (Apnea-Hypopnea Index) for coverage of Continuous Positive Airway Pressure (CPAP) therapy. Is it two recorded hours or two hours of actual sleep time?

Key Points

We're confused by the time requirements to establish the AHI (Apnea-Hypopnea Index) for coverage of Continuous Positive Airway Pressure (CPAP) therapy. Is it two recorded hours or two hours of actual sleep time?

The National Coverage Determination for CPAP therapy indicates that "The AHI is equal to the average number of episodes of apnea and hypopnea per hour and must be based on a minimum of two hours of sleep recorded by polysomnography using actual recorded hours of sleep." The time cannot be extrapolated or calculated.