TABLE 3.

Univariate and multivariate COX regression.

	Univariate analysis		Multivariate analysis
	Unadjusted HR (95% CI)	P -value	Adjusted HR (95% CI)	P -value
Age		<0.001		<0.001
≤52	Reference
52–66 (including 66)	2.5 (1.5–4.0)		1.8 (1.1–3.0)	0.016
66–76 (including 76)	4.5 (2.9–7.0)		3.0 (1.8–4.7)	<0.001
>76	6.6 (4.3–10.3)		4.4 (2.8–7.0)	<0.001
ECI score		<0.001		<0.001
≤3	Reference
3–8 (including 8)	1.6 (1.1–2.3)		1.3 (0.9–1.9)	0.226
8–14 (including 14)	2.2 (1.5–3.1)		1.6 (1.1–2.3)	0.009
>14	3.1 (2.2–4.4)		2.1 (1.5–3.1)	<0.001
Tracheostomy time		0.001		0.004
≤4 days	Reference
5–10 days	0.9 (0.6–1.3)		0.8 (0.6–1.2)	0.369
≥11 days	1.4 (1.0–2.0)		1.3 (0.9–1.8)	0.181
ICU type on the day of tracheostomy		<0.001		0.08
TSICU/SICU	Reference
CCU/CSRU	1.9 (1.4–2.5)
MICU	1.5 (1.2–2.0)
Admission type		0.063		0.196
Emergency	Reference
Urgent	1.8 (1.1–2.7)
Selective	1.2 (0.8–1.7)
Gender		0.922		/
Female	Reference
Male	1.0 (0.8–1.2)
SAPSII		<0.001		0.012
≤36	Reference
36–46 (including 46)	2.5 (1.6–3.8)		1.5 (1.0–2.3)	0.062
46–57 (including 57)	3.7 (2.5–5.5)		1.9 (1.2–2.9)	0.005
>57	4.4 (3.0–6.6)		1.9 (1.2–3.0)	0.003
SOFA		0.002		0.965
≤4	Reference
4–6 (including 6)	1.3 (0.9–1.9)
6–9 (including 9)	1.5 (1.1–2.1)
>9	1.8 (1.3–2.5)
GCS in admission		0.814		/
≥12	Reference
9–11	0.9 (0.7–1.3)
≤8	0.9 (0.7–1.2)

HR, hazard ratio; CI, confidence interval; ECI, Elixhauser Comorbidity Index; CCU, coronary care unit; CSRU, cardiac surgery recovery unit; MICU, medical intensive care unit; TSICU, trauma/surgical intensive care unit; SICU, surgical intensive care unit; SOFA, Sequential Organ Failure Assessment; SAPSII, Simplified Acute Physiology Score; GCS, Glasgow Coma Scale.