CMS has added new language to its National Coverage Determination (NCD) for home CPAP therapy for OSA, with revisions mostly coming in the form of updates to its Respiratory Disturbance Index (RDI) criteria. Regarding RDI, the National Coverage Determination for Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea (240.4) states:

An initial 12-week period of CPAP is covered in adult patients with OSA if either of the following criteria using the [Apnea-Hypopnea Index] AHI or RDI are met:

a. AHI or RDI greater than or equal to 15 events per hour, or

b. AHI or RDI greater than or equal to 5 events and less than or equal to 14 events per hour with documented symptoms of excessive daytime sleepiness, impaired cognition, mood disorders or insomnia, or documented hypertension, ischemic heart disease, or history of stroke.

The AHI or RDI is calculated on the average number of events per hour. If the AHI or RDI is calculated based on less than 2 hours of continuous recorded sleep, the total number of recorded events to calculate the AHI or RDI during sleep testing must be at a minimum the number of events that would have been required in a 2-hour period.

The revised NCD can be read in its entirety here.

*Edits inserted November 5, 8:30 am