Subgroup analysis
Subgroup analysis was performed to investigate the potential factors that affected the IOC2 target attainment in the DEX group. Among patients who attained the IOC2 target in the DEX group, we analysed their age, sex, BMI and ASA score. There was no significant difference in the attainment of the IOC2 target value during subgroup analyses for age: age ≤ 60 vs age > 60 years (Kaplan–Meier curves within subgroups in the dexmedetomidine (DEX) group according to (