Many patients starting out CPAP therapy go noncompliant because they have various issues or concerns with the machine, mask comfort, etc.

Insurance companies are tired of paying thousands of dollars in machines and supplies that don't go used, so they instead 'rent' the machines from medical equipment suppliers, and use the machine's usage data to determine that you are still using it (and thus continue to pay for treatment). Typically after a year or so of usage they get 'paid for' but there's still ongoing compliance monitoring to get insurance to pay for supplies.

The sleep lab and sleep doctors can also remotely review the usage and make adjustments as needed. One example is using the humidity sensors in ResMed units to adjust the humidification settings remotely. I was with a doctor that showed usage logs together and noted the bedroom was severely dry and thus we needed to adjust the humidifier to run hotter to compensate.