Table 4:

Multivariable model of preoperative and hospital factors associated with total hospital length of stay and cost

	Length of stay		Cost
	Ratio (95% CI)	p	Ratio (95% CI)	p
Age at ASO (per day)	1.03 (1.03 to 1.04)	<0.001	1.02 (1.02 to 1.03)	<0.001
Genetic condition	1.98 (1.67 to 2.35)	<0.001	1.95 (1.64 to 2.30)	<0.001
Prematurity	1.32(1.22 to 1.44)	<0.001	1.27 (1.17 to 1.38)	<0.001
Preoperative prostaglandin infusion	1.01 (0.96 to 1.07)	0.65	1.00 (0.95 to 1.05)	1.00
Preoperative inotrope infusion	1.06 (0.83 to 1.34)	0.65	1.38 (1.09 to 1.74)	0.008
Preoperative mechanical ventilation	1.12 (1.07 to 1.19)	<0.001	1.17 (1.11 to 1.24)	<0.001
Balloon atrial septostomy	0.84 (0.80 to 0.88)	<0.001	0.84 (0.81 to 0.88)	<0.001
Hospital average age at ASO (per day)	1.04 (1.01 to 1.08)	0.004	1.07 (1.03 to 1.11)	<0.001
Hospital propensity to pursue BAS	0.89 (0.55 to 1.42)	0.41	0.74 (0.41 to 1.32)	0.31
Hospital propensity for mechanical ventilation	1.05 (0.81 to 1.37)	0.70	0.97 (0.70 to 1.35)	0.87
Hospital propensity for prostaglandin	0.90 (0.70 to 1.16)	0.41	1.32 (0.97 to 1.81)	0.08
Hospital CT surgical volume (per 100 cases)	0.96 (0.92 to 1.00)	0.05	0.96 (0.91 to 1.01)	0.10

Abbreviations: ASO arterial switch operation, BAS balloon atrial septostomy, CI confidence interval, CT cardiothoracic