Respiratory Disturbance Index

Respiratory Disturbance Index (RDI) includes apneas and hypopneas, and may also include other respiratory disturbances such as snoring arousals, hypoventilation episodes, desaturation events, etc. They are often identical, but depending upon what is scored, the RDI may be larger than the AHI.

RDI, Respiratory Disturbance Index for sleep apnea: 5 to 20 events per hour is Mild SDB 20 to 40 events is Moderate SDB More than 40 events is Severe SDB (from Barry Krakow, MD, Sound Sleep,Sound Mind, page 245)