Table 4. Multivariate analysis performed on five factors affecting the cumulative incidence of extubation.

	Hazard ratio	95% confidence interval	p -Value
Age (mo)	0.993	0.762–1.293	0.96
Westley croup score at emergency department	1.589	0.796–3.172	0.19
Difference in internal diameter between the selected tube and age-appropriate size (mm)	0.092	0.011–0.798	0.03
Presence of endotracheal tube leakage immediately after intubation	0.359	0.025–5.159	0.45
Pediatric index of mortality 2 on PICU admission	2.593	0.153–44.050	0.51

Abbreviation: PICU, pediatric intensive care unit.