TABLE 3

Individual questions for component 5 (sleep disturbance) in the Pittsburgh Sleep Quality Index (PSQI) questionnaire

VariablePoor sleep quality (PSQI>5)Good sleep quality (PSQI≤5)p-value
Cannot get to sleep within 30 min2 (1–3)0 (0–1)<0.0001
Wake up in the middle of the night or early morning3 (2–3)2 (0–3)0.002
Have to get up to use the bathroom3 (2–3)3 (2–3)0.45
Cannot breathe comfortably2 (0–3)0 (0–2)0.02
Cough or snore loudly3 (1–3)1 (0–3)0.07
Feel too cold1 (0–3)1 (0–1.25)0.02
Feel too hot1 (0–2.5)0 (0–0.25)0.0004
Have bad dreams1 (0–3)0 (0–0)0.14
Have pain1 (0–3)0 (0–2)0.006
Other reasons1 (0–3)0 (0–1)0.001

Data presented as median (interquartile range), unless stated otherwise. Scores are as follows. 0: not during the past month; 1: less than once a week; 2: one or twice a week; 3: three or more times a week.