Table 1 Sleep variables in Pittsburgh Sleep Quality Index Past Week (PSQI_PW) questionnaire
Sleep variables | Definition | Scale |
|---|---|---|
PSQI_PW | Global score (overall sleep quality) | 0 (better) to 21 (worse) |
Sleep Duration | Hours of sleep every night | 0 (better; if duration ≥7 h) to 3 (worse; if duration < 5 h) |
Sleep Latency | Minutes to accomplish full transition from wakefulness to sleep | 0 (better; if latency ≤15 min) to 3 (worse; if latency > 60 min) |
Day Dysfunction due to sleepiness | Inability to stay awake and keep up enthusiasm during daytime. | Binary: yes / no |
Sleep Efficiency | The percentage of time in bed that one is asleep | Range: 0 (better) to 3 (worse) |