How to Read Your CPAP Data Report — A Licensed RRT Explains Every Number

By Yash, RRT — Licensed Respiratory Therapist & Owner, MyRespCo

Your CPAP machine records detailed data every night. If you use a ResMed AirSense 10 or 11, this data syncs to the myAir app automatically. If you have an older machine, it's stored on your SD card. Either way, understanding what those numbers mean — and what they should be — is one of the most powerful things you can do for your therapy outcomes.

The 4 Key Metrics in Your CPAP Data

1. AHI — Apnea-Hypopnea Index

This is the most important number. AHI on CPAP measures how many breathing events (apneas and hypopneas) per hour occurred while you were using the machine. This is called your residual AHI.

• AHI <5: Excellent. Therapy is effectively controlling your sleep apnea.
• AHI 5–10: Acceptable. Therapy is working but pressure or mask fitting may need optimization.
• AHI >10: Suboptimal. Pressure range, mask leak, or machine mode likely needs adjustment.

For CDL/DOT compliance, your residual AHI must be below 5 events per hour.

2. Usage Hours

How many hours the machine was running each night. This is what determines insurance compliance and, for CDL drivers, FMCSA compliance.

• Insurance compliance (typical): ≥4 hours on ≥70% of nights
• CDL/FMCSA compliance: ≥4 hours on ≥70% of monitored nights
• Clinical recommendation: Use CPAP for your full sleep duration — 7–8 hours nightly

3. Mask Leak (Large Leak)

The myAir app and CPAP data report mask leak in liters per minute (L/min). A small amount of intentional leak at the mask vent is normal and expected — this is how CO₂ is expelled. What you're monitoring is unintentional leak from a poor seal.

• <24 L/min: Acceptable
• 24–40 L/min: Elevated — mask fit should be checked
• >40 L/min: Significant — therapy delivery is compromised, mask refitting required immediately

High mask leak directly causes poor AHI — if your residual AHI is elevated, check your leak data first.

4. Pressure

For AutoSet machines, this shows the median and 95th percentile pressure delivered across the night. If your 95th percentile pressure is consistently hitting your maximum setting (e.g. consistently at 20 cmH₂O on a 4–20 range), your pressure ceiling may be too low for your anatomy — and this limits therapy effectiveness.

What a Good Night Looks Like

Common Patterns and What They Mean

• AHI spikes on certain nights: Often correlated with alcohol use, sleeping on your back (positional apnea), or nasal congestion
• Consistently high leak + high AHI: Mask fit issue — try different mask style or cushion size
• Normal AHI but waking unrefreshed: May indicate REM-related events, pressure is too low at certain sleep stages, or a non-apnea sleep issue
• Pressure consistently at max setting: Upper pressure limit may need adjustment — discuss with your RT or physician

Want Your Data Professionally Reviewed?

MyRespCo's $49.99 RT Consultation includes a full review of your CPAP therapy data — AHI trends, leak patterns, pressure analysis, and specific recommendations to optimize your therapy. Bring your myAir login or SD card data to the session.

For CDL drivers: this same data review is formatted into a DOT Medical Examiner compliance report as part of the $49.99 service.

→ Book an RT Consultation — $49.99
→ CDL CPAP Compliance Hub
→ What Is AHI?
→ Refurbished CPAP Buyer's Guide