Why in the world does a CPAP machine need a modem?

Most have a cf slot to store the sleep data, it’s how the doctor / clinician can see if it’s working, make adjustments to pressure etc. but for convenience they can just upload the data directly.

They also do OTA updates.

However they also can perform an enforcement function: compliance. Insurers will penalize users of the device for not using it enough.

This isn’t something I know much about just have seen it discussed, I don’t think all jurisdictions allow insurers to access this data for enforcement but it does seem to happen in USA.

I think what happens is the insurers agree to pay for the device in installments. But they will cancel those payments if the person isn’t using it.

But disabling the modem won’t fix that problem, you’d still get caught by the cf recorded data, or failing to provide it.

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.