TABLE 5

Obstructive sleep apnea severity

Index	Calculation
Apnea–hypopnea index (AHI)	$\text{[math]}$
Respiratory disturbance index	$\text{[math]}$
Respiratory event index	$\text{[math]}$

Respiratory event index is typically used for home sleep apnea testing as it is based on monitoring time as distinct from actual sleep time.