Skip to main content

Table 1 Objective Sleep Parameter Definitions

From: Potential mechanisms underlying sleep disturbance in young people with borderline personality disorder features: an exploratory study

Sleep Parameter Definition
Bedtime Time at which an individual started trying to fall asleep. This was pre-set based on sleep diary data and visual inspection of actigraphy data
Rise time Time of final awakening, after which the individual did not attempt to fall back asleep. This was pre-set based on sleep diary data and visual inspection of actigraphy data
Time in Bed The total number of minutes elapsed between bedtime and rise time
Total Sleep Time (TST) The total number of minutes scored as sleep
Sleep Efficiency (SE) Total sleep time divided by time in bed, expressed as a percentage
Sleep Onset Latency (SOL) The time elapsed between bedtime and the start of the sleep period (the first epoch of the first section of 5 consecutive minutes scored as sleep)
Wake After Sleep Onset (WASO) Time spent awake during time in bed after the start of the sleep period
Total Sleep Time Variability Coefficient of variation (standard deviation/mean) for total sleep time within each participant
Time in Bed Variability Coefficient of variation for time in bed within each participant
Bedtime Variability Individual standard deviation for bedtime across the 10-day period
Rise time Variability Individual standard deviation for rise time across the 10-day period
  1. Note. Coefficient of variation (CV) has been used previously in sleep research in young people with mental illnesses ([38, 56]). CV can only be calculated with true ratio data. Hence, intra-individual variability in bed and rise times were assessed using individual standard deviations