Table 3. Comparison of operation time in patients with vs. without preoperative FN imaging using 3D-DESS-WE-MRI.

Method	Group	No.	Operation time #1			Operation time #2
			Median (IQR), min	Coefficient estimate (95% CI)	P	Median (IQR), min	Coefficient estimate (95% CI)	P
Before PS matching	MRI (-)	165	30 (30.0 to 40.0)	Ref.	< 0.001	40.0 (30.0 to 45.0)	Ref.	< 0.001
	MRI (+)	105	25.0 (25.0 to 30.0)	-0.28 (-0.35 to -0.21)		40.0 (35.0 to 55.0)	0.21 (0.14 to 0.29)
After PS matching	MRI (-)	65	35 (30.0 to 45.0)	Ref.	< 0.001	40.0 (30.0 to 50.0)	Ref.	0.653
	MRI (+)	65	25 (25.0 to 30.0)	-0.51 (-0.52 to -0.49)		35.0 (35.0 to 50.0)	0.02 (-0.07 to 0.12)
Stabilized IPTW analysis	MRI (-)	133	30 (30.0 to 40.0)	Ref.	< 0.001	35.0 (30.0 to 45.0)	Ref.	0.207
	MRI (+)	83	25 (25.0 to 30.0)	-0.28 (-0.35 to -0.21)		35.0 (35.0 to 50.0)	0.13 (-0.07 to 0.34)

Time to FN identification (operation time #1) and time to tumor removal (operation time #2) were transformed using natural log due to skewed distribution. Coefficient estimate (95% CI): Regression coefficient estimate, 95% confidence intervals (CIs). Statistical analysis using a generalized estimating equation (PS matching), or a logistic regression model with a stabilization (trimming) of extreme propensity scores (< 0.1 or > 0.9) (stabilized IPTW analysis).

FN = facial nerve, 3D-DESS-WE-MRI = three-dimensional double-echo steady-state water-excitation sequence magnetic resonance imaging, IQR = interquartile range, Ref. = reference, PS = propensity score, MRI = magnetic resonance imaging, IPTW = inverse probability of treatment weighting