Table 4.

Association between Variables Measured during CPX Testing and Mortality^* (Multivariable Analyses)

Parameters	Hazard Ratio (95% Confidence Interval)	Multivariate Wald chi-square value†	Overall Model c-index (Optimism Corrected)
Percent predicted peak VO2, per 5% change	0.81 (0.78–0.84)	133	0.707 (0.678–0.736)
Exercise duration, min	0.84 (0.82–0.87)	131	0.712 (0.681–0.744)
Relative peak VO2, mL·kg−1·min−1	0.84 (0.82–0.87)	133	0.711 (0.682–0.740)
Absolute peak VO2, per 100 ml/min−1	0.86 (0.84–0.88)	112	0.699 (0.670–0.723)
Peak RER, per 0.1 units	0.94 (0.86–1.04)	1 (p=0.24)	0.612 (0.581–0.643)
Ventilatory efficiency (VE – VCO2 slope), per 5 units	1.25 (1.19–1.31)	90	0.666 (0.635–0.696)
Heart rate reserve, per 5 beats/min−1	0.89 (0.86–0.91)	74	0.673 (0.644–0.703)
VO2 at VAT, mL·kg−1·min−1	0.82 (0.78–0.86)	56	0.674 (0.640–0.707)
Peak oxygen pulse, ml.beat−1	0.87 (0.84–0.90)	59	0.662 (0.632–0.692)
Oxygen uptake efficiency slope (all data), per 100 units	0.91 (0.89–0.93)	78	0.670 (0.639–0.700)

^*p values significant at p < 0.0001 except where otherwise indicated.

^†Adjusted for age and sex.

RER = respiratory exchange ratio; other abbreviations as in Tables 2 and 3.