TABLE 3.

Patient use of controlled analgesia pump during the first 24 h after surgery.

Variables	Acetaminophen (n = 116)	Placebo (n = 119)	p value
Times of button-pressing
Modified intention-to-treat analysis, median [IQR]	4.0 (1.0–11.0)	6.0 (2.0–13.0)	0.10
Per-protocol analysis, median [IQR]	4.0 (1.0–10.0)	6.0 (2.0–13.0)	0.02
Times of effective button-pressing
Modified intention-to-treat analysis, median [IQR]	4.0 (1.0–9.0)	6.0 (2.0–13.0)	0.07
Per-protocol analysis, median [IQR]	4.0 (1.0–8.0)	6.0 (2.0–13.0)	0.01

IQR, interquartile range.