TableĀ 1

Description of sleep variables

Total sleep time (min)Amount of time asleep
Sleep Onset Latency (min)Length of time from lights out to first episode of stage 2 sleep
Wake After Sleep Onset (min)Number of minutes of recorded wake following first episode of stage 2 sleep
Number of awakenings (over TSP)Number of wake bouts following first episode of stage 2 sleep
Number of arousalsNumber of arousals over the entire sleep period
REM LatencyLength of time to first REM stage
AHI IndexNumber of apnoea or hypopnia events per hour of sleep
Percentage of N1 (of TST)Percentage of recorded stage 1 sleep over the total time asleep
Percentage of N2 (of TST)Percentage of recorded stage 2 sleep over the total time asleep
Percentage of N3 (of TST)Percentage of recorded slow wave sleep over the total time asleep
Percentage of REM (of TST)Percentage of recorded REM sleep over the total time asleep
Percentage of WAKE (of TSP)Percentage of recorded wake over the total sleep period (ie, how long they were awake following first episode of stage 2 sleep)
  • REM, rapid eye movement; TSP, total sleep period; TST, total sleep time.