Table 4.

The multiple liner regression analysis for the log-transformed values of the length of ICU stay and hospital stay in survived patients

	Ratio	95% confidence interval		p value
Sub-analysis 1: multiple linear regression in survived patients for the length of ICU stay
(Closed ICU/open ICU) *	0.80	0.75	0.87	< 0.001
Sub-analysis 2: multiple linear regression in survived patients for the length of hospital stay
(Closed ICU/open ICU) *	0.98	0.90	1.07	0.642

*Adjusted by both patient backgrounds and treatment variables (exactly the same covariates in main analysis)