Table 4.

Univariate and adjusted logistic regression for variables at 3700 m (N = 363)

	Risk factors	β-coefficient	Odds ratio	(95% CI)		p value
				Lower	Upper
Univariate logistic regression
	HR	0.022	1.022	1.003	1.042	0.027*
	SpO2	−0.081	0.922	0.851	1.000	0.049*
	CO	0.422	1.524	1.195	1.944	0.001**
Left VA	Vd	0.052	1.053	1.001	1.108	0.046*
	PI	−1.562	0.210	0.047	0.944	0.042*
	RI	−4.476	0.011	0.000	0.591	0.026*
BA	Vm	0.032	1.033	1.005	1.061	0.018*
	Vd	0.044	1.036	1.001	1.071	0.035*
Asymmetry of VAs	ΔVd	0.063	1.065	1.011	1.122	0.018*
Adjusted logistic regression
Model 1
	HR	0.025	1.025	1.005	1.045	0.012*
Model 2
	HR	0.023	1.023	1.003	1.044	0.026*
	ΔVd	0.065	1.068	1.013	1.126	0.015*
Model3
	CO	0.417	1.517	1.189	1.937	0.001**
	ΔVd	0.063	1.065	1.009	1.124	0.022*

*p is 0.05 or less, **p is 0.01 or less

Model 1: Adjusted by primary variables (SpO₂, V_d in left side VA and BA);

Model 2: Adjusted by primary variables and an asymmetry data (ΔV_d);

Model 3: Avoided the colinearity between HR and CO, indicated that CO and ΔV_d were independent risk factors for HAH;

We just listed the variable with a p < 0.05