Low Stroke Volume Index in Healthy Young Men Is Associated with the Incidence of Acute Mountain Sickness after an Ascent by Airplane: A Case-Control Study

Table 3

The incidence of AMS according to SVi.

	Incidence of AMS, IRR (95% CI)
		Decreasing category of SVi
	Continuous	Highest tertile	Middle tertile	Lowest tertile
No. of cases	238	31	61	146
No. of controls	351	165	136	50
Model 0	0.932 (0.922-0.942)	1 (reference)	1.958 (1.333-2.876)	4.710 (3.375-6.572)
Model 1	0.933 (0.922-0.943)	1 (reference)	1.964 (1.339-2.879)	4.619 (3.311-6.444)
Model 2	0.936 (0.925-0.948)	1 (reference)	1.872 (1.276-2.747)	4.097 (2.892-5.803)

IRR = Incidence Rate Ratios; CI = confidence interval; other abbreviations are as in Table 1. Model 0: unadjusted; model 1: adjusted by age, BMI, smoking, and drinking; model 2: adjusted by model 1 plus HR, MAP, SpO₂, and E/A.