CPAP compliance data: what your machine is actually tracking

Modern CPAP machines log usage hours per night, mask leak rate, residual AHI (events still occurring despite treatment), and pressure delivered — all timestamped, and typically exportable via SD card or a companion app your physician can review remotely.

The most commonly cited compliance threshold — 4 hours of use per night, on 70% of nights in a 30-day window — originated as an insurance-reimbursement standard, not a clinical claim that anything under 4 hours provides zero benefit. It's a coverage bar, not a scientifically ideal cutoff.

Residual AHI is arguably more clinically useful than raw hours-used: a high number of hours with a still-elevated event count usually points to a leak or pressure problem worth adjusting, not a reason to assume treatment is failing outright.

Leak rate above the device's threshold is the most common reason for a technically-compliant-hours report to still come with poor symptom improvement — worth checking specifically if you're wearing the mask all night but not feeling the benefit you expected.