Measures
The demographic characteristics regarding the study participants were recorded at the time of admission. The participants' baseline sleep quality was obtained by averaging preoperative three measurements of the RCSQ (Richards-Campbell Sleep Questionnaire) score. The vital signs (respiration rate [RR], heart rate [HR], diastolic blood pressure [DBP], and systolic blood pressure [SBP]) were also obtained via ECG monitor and arterial or cuff manometer by averaging three measured results at four corresponding time points respectively.