Table 5.

Segmented time-series regression sensitivity analysis for the effect of a neurocritical care analgesia and sedation protocol on healthcare utilisation and costs after removing high-leverage outliers, 2011–2015 (N = 1,197).

Outcomes	Model Variable (95% CLs)
	Intercepta	Baseline Linear Trendb	Level Changec	Post-protocol Linear Trendd
Total hospital days	23.0 (15.9, 30.0)	−0.7 (−2.8, 1.4)	−0.5 (−11.3, 10.3)	0.2 (−2.0, 2.3)
P-value	<0.001	0.49	0.93	0.88
NCCU days	11.7 (8.9, 14.5)	−0.5 (−1.2, 0.2)	2.7 (−0.4, 5.7)	0.2 (−0.6, 1.0)
P-value	<0.001	0.13	0.08	0.58
Ventilator days	7.4 (5.0, 9.8)	−0.5 (−1.0, 0.0)	2.2 (0.02, 4.2)	0.3 (−0.3, 0.9)
P-value	<0.001	0.07	0.03	0.25
Total hospital costs, USDe	83,882.8 (64,503.7, 103,262.0)	−2,557.9 (−6,706.0, 1,590.3)	10,026.5 (−5,673.8, 25,726.8)	541.7 (−3,923.9, 5,007.4)
P-value	<0.001	0.20	0.19	0.80
NCCU costs, USDe	31,524.7 (25,027.7, 38,021.7)	−1,385.7 (−2,989.7, 218.3)	7,640.8 (−395.3, 15,677.0)	687.3 (−1,196.4, 2,571.0)
P-value	<0.001	0.08	0.06	0.44
Respiratory care costs, USDe	4,841.1 (3,432.4, 6,249.8)	−285.8 (−600.9, 29.4)	1,759.5 (179.8, 3,339.2)	184.8 (−228.5, 598.1)
P-value	<0.001	0.07	0.03	0.35

Abbreviation: CLs, Confidence limits; NCCU, neurocritical care unit.

^aThe intercept is the model estimate for the outcomes in the first quarter of the study period.

^bBaseline linear trend describes the change in the outcome per quarter in the pre-protocol change period (2/1/2011 to 1/31/2013).

^cLevel change is the estimated instantaneous change in the outcome in the first post-protocol period (2/1/2013 to 4/30/2013) compared with the expected rate based on the baseline trend.

^dPost-protocol linear trend describes the change in trend in the post-protocol change period (5/1/2013 to 1/31/2015); the trend in the post-protocol change period is the difference between the pre-protocol and post-protocol slopes of the outcome.

^eDollars are represented as 2015 fiscal year dollars.