TABLE 4.

MULTIVARIATE COX PROPORTIONAL HAZARD SURVIVAL MODEL ASSESSING THE PREDICTIVE VALUE OF o₂max < 8.3 ml/min/kg

	HR	95%CI	P Value
o2max below threshold	3.24	1.10–9.56	0.03
Age, yr	1.04	1.00–1.08	0.08
Male sex	1.29	0.62–2.69	0.50
Ever smoker	1.33	0.71–2.48	0.37
Baseline FVC%	0.93	0.72–1.21	0.58
Baseline DlCO%	0.66	0.49–0.90	0.01

Definition of abbreviations: CI = confidence interval; Dl_CO% = diffusion capacity for carbon monoxide percent predicted; FVC% = forced vital capacity percent predicted; HR = hazard ratio; o₂max = maximal oxygen consumption during cardiopulmonary exercise testing.

n = 103.