Table 4. Statistical significance between predisposing factors and perioperative complications.

Predisposing factors	P values by complications
	Hypothermia	Hypotension		Bradycardia		Postoperative complication
		Relative	Absolute	Relative	Absolute	Major	Minor
GMFCS level	< 0.001	0.004	< 0.001	0.749	0.453	< 0.001	< 0.001
Age*	0.032	< 0.001	< 0.001	< 0.001	< 0.001	0.197	0.444
Hip osteotomy*	< 0.001	0.114	0.698	0.284	0.072	0.106	0.005
Geographic type of CP*	< 0.001	0.002	0.086	0.598	0.942	0.760	0.578
History of pneumonia*	0.493	0.724	< 0.001	0.543	0.643	< 0.001	0.286
Operation time†	< 0.001	< 0.001	0.005	< 0.001	0.056	0.437	0.548

^*Analyzed by Cochran-Mantel-Haenszel test adjusting for GMFCS level as a control variable; ^†Analyzed by analysis of covariance adjusting for GMFCS level and hip surgery as control variables. GMFCS, gross motor function classification system; CP, cerebral palsy.