Table 3

Parameter estimates, SEs and p values from the full and most parsimonious segmented regression models predicting mean monthly intraoperative OME/hour, PACU OME and 48 hours postoperative OME

	Intraoperative OME/hour				PACU OME				48 hours postoperative OME
	Coefficient	SE	t-statistics	P value	Coefficient	SE	t-statistics	P value	Coefficient	SE	t-statistics	P value
Parsimonious regression model
intercept β0	44.05	2.34	18.86	<0.001	34.36	0.52	66.24	<0.001	184.93	3.34	55.39	<0.001
intervention effect β 2	0.52	3.34	0.16	0.875	−3.88	0.74	−5.24	<0.001	−22.59	4.77	−4.74	<0.001
Full segmented regression model
Intercept β 0	44.66	4.39	10.15	<0.001	35.51	0.98	36.4	<0.001	177.92	6.28	28.34	<0.001
Baseline trend β 1	0.11	0.67	0.16	0.87	0.21	0.15	1.39	0.165	−1.27	0.96	−1.32	0.188
Intervention effect β 2	2.97	6.51	0.46	0.649	−4.84	1.45	−3.35	0.001	−19.81	9.31	−2.13	0.033
Trend after intervention β2	−0.49	0.67	−0.73	0.465	−0.03	0.15	−0.2	0.844	0.68	0.96	0.71	0.479

OME, oral morphine equivalents; PACU, postanaesthesia care unit.