Table 2.

The association between mechanical power and 28-day ventilator-free days and ICU mortality

	28-day Ventilator-free days (IMV)			ICU mortality
	n	SHR (95% CI)	p value	n	OR (95% CI)	p value
Univariable models
Entire cohort
Mechanical power	304	0.89 (0.84, 0.94)	< 0.001	306	1.26 (1.12, 1.41)	< 0.001
Multivariable models
Entire cohort
Mechanical Power	304	0.93 (0.87, 0.98)	0.013	306	1.12 (0.94, 1.32)	0.20
Subgroup excluding children with neurologic death
Mechanical Power	291	0.91 (0.86, 0.97)	0.002	293	1.22 (1.01, 1.46)	0.036
Age Subgroups
< 2 years: Mechanical Power	149	0.89 (0.82, 0.96)	0.005	151	1.19 (0.97, 1.46)	0.087
≥ 2 years: Mechanical Power	153	0.97 (0.84, 1.12)	0.68	153	0.94 (0.69, 1.29)	0.71
PARDS severity subgroups
Resolved/Mild PARDS:  Mechanical Power	163	0.90 (0.80, 1.03)	0.12	164	1.00 (0.73, 1.37)	0.99
Moderate/severe PARDS:  Mechanical Power	141	0.94 (0.87, 1.03)	0.18	142	1.25 (0.99, 1.59)	0.059

All estimates are per 0.1 J·min⁻¹·Kg⁻¹ predicted body weight change in mechanical power. All models adjusted for center-level effects. Multivariable models control for the pre-specified pediatric acute respiratory distress syndrome (PARDS) severity of illness score, a comorbidity of bronchopulmonary dysplasia, height, PCO₂, and mode of ventilation. The pre-specified PARDS severity of illness score adjusts for immunocompromised conditions, the 6-h PaO₂/FiO₂ ratio, and the fluid balance, vasopressor-inotrope score, and organ dysfunction on the first day of PARDS. There were 2 children without length of ventilation data that were excluded from the VFD models. There were 2 children missing age excluded from the age subgroup models. IMV: invasive mechanical ventilation