Risk over time and risk factors of intraoperative respiratory events: a historical cohort study of 14,153 children

Table 4 Multivariate Cox regression of wheezing based on period of anesthesia (n = 42,055)

Variable	All periods (101)	Induction (48)	Maintenance (41)	Emergence (12)
Variable	Adjusted hazard ratio (95% CI) p-value	Adjusted hazard ratio (95% CI) p-value	Adjusted hazard ratio (95% CI) p-value	Adjusted hazard ratio (95% CI) p-value
Respiratory disease (ref = no)	1^a < 0.001
URI	3.5 (2.0, 6.2)^b	_	_	_
Pulmonary disease	2.9 (1.7, 5.1)^b
ASA classification (ref = 1)	1^a 0.014	_	_	_
2	2.0 (0.99, 3.9)^a
3	2.9 (1.4, 6.1)^b

p-value from likelihood ratio test, ASA: American Society of Anesthesiologist; CI: Confidence interval; URI: Upper respiratory tract infection, hazard ratios within columns and variables that have no superscript (^a ^b) in common differ significantly at p < 0.05 (Wald test).

ISSN: 1471-2253