Table 2.

Associations Between IV Acetaminophen and PCA Attempts, Pain Scores, and IV Morphine Equivalents.

Characteristic		Model 1	Model 2
PCA attempts	1st 8 hours	1.307 (0.701, 2.437) P = .400	1.137 (0.661, 1.956) P = .641
	2nd 8 hours	0.654 (0.341, 1.255) P = .202	0.664 (0.321, 1.374) P = .269
	3nd 8 hours	1.109 (0.573, 2.145) P = .759	1.520 (0.862, 2.679) P = .148
Average pain score	1st 8 hours	0.781 (0.436, 1.399) P = .406	0.745 (0.349, 1.591) P = .448
	2nd 8 hours	1.548 (0.835, 2.869) P = .165	2.171 (1.046, 4.507) P = .037
	3nd 8 hours	1.072 (0.555, 2.07) P = .837	1.304 (0.647, 2.627) P = .458
Highest pain score	1st 8 hours	0.806 (0.492, 1.32) P = .392	0.708 (0.377, 1.331) P = .284
	2nd 8 hours	1.404 (0.828, 2.38) P = .208	1.908 (0.983, 3.705) P = .056
	3nd 8 hours	1.128 (0.645, 1.973) P = .672	1.253 (0.676, 2.321) P = .473
PCA IV ME	1st 8 hours	0.701 (0.468, 1.05) P = .085	0.697 (0.486, 0.999) P = .049
	2nd 8 hours	0.799 (0.526, 1.214) P = .293	0.847 (0.548, 1.309) P = .456
	3nd 8 hours	0.849 (0.550, 1.311) P = .460	0.955 (0.600, 1.521) P = .848
Total IV ME	1st 8 hours	0.599 (0.408, 0.878) P = .009	0.610 (0.432, 0.86) P = .005
	2nd 8 hours	0.712 (0.482, 1.052) P = .088	0.756 (0.506, 1.13) P = .173
	3nd 8 hours	0.775 (0.516, 1.163) P = .218	0.872 (0.574, 1.325) P = .521
Total IV ME in 24 h		0.692 (0.486, 0.987) P = .042	0.739 (0.523, 1.045) P = .087

Values are reported in odds ratios using gamma regression. Statistical significance (bolded) was set at the 95% level of confidence (α = 0.05). Model 1: unadjusted; Model 2: adjusted for age, sex, and race.

IV ME = intravenous morphine equivalents; PCA = patient controlled analgesia.