Table 1.

Definition of the sleep parameters

Sleep parameters	Definition
Wake after sleep onset (WASO)	Amount of total wake time between sleep-onset and final wake-up
Total sleep time (TST)	Amount of actual sleep time in a sleep period
Sleep onset latency (SOL)	Time period measured from light-off to the beginning of sleep
Sleep efficiency (SE)	Ratio of total sleep time to time in bed
Apnea-hyponea index (AHI)	An index used to assess severity of sleep apnea based on total number of complete cessations (apnea) and partial obstructions (hypopnea) of breathing occurring per hour of sleep
Periodoc limb movement index (PLMI)	An index used to assess severity of periodic limb movement disorder based on total number of periodic limb movements occurring per hour of sleep