Do you grade severity of OSA by AHI or RDI?

We recently changed, per AASM guidelines, to reporting both AHI3a and AHI4. Since most sleep-disordered breathing events will qualify with the 3a decision, as it includes arousals, we have stopped reporting an RDI. If there are events that don't meet the 3a hypopnea definition, we might comment on i...

Let's first agree on the basic definitions:

AHI: Apnea hypopnea Index:

• Apneas: Complete cessations (>90%) of airflow lasting for at least 10 seconds.
• Hypopneas: Partial reductions (>30-50%) in airflow leading to a decrease in oxygen saturation (by at least 3% or 4%) or arousal from sleep.
• AHI = (nu...

While 3% and 4% hypopnea and apneas as well as RERA are useful they are flawed in patients with long apneas. For instance, someone who has one-minute apneas can have an AHI of 60/hr while someone with 30-second apneas can calculate to 120/hr. Clearly, the 1-minute apneas are more severe and the AHI ...

AASM goes by AHI.

AHI.