Table 3.
Stepwise Regression for Ventilation-Free and Absolute Survival: Final Multivariate Analysis Model of Maximum Likelihood Estimates
| Parameter | Parameter Estimate | Standard Error | Chi-Square | P Value | Hazard Ratio | 95% CI of Hazard Ratio |
|---|---|---|---|---|---|---|
| Ventilation-free survival |
||||||
| Age, yr | −0.06332 | 0.02112 | 8.9861 | 0.0027 | 0.939 | 0.901–0.978 |
| Tw Pdi, cm H2O | −0.13279 | 0.03104 | 18.3039 | <0.0001 | 0.876 | 0.824–0.931 |
| Sn Pdi, cm H2O | −0.03014 | 0.00996 | 9.1576 | 0.0025 | 0.970 | 0.952–0.989 |
| Sn Pes, cm H2O | 0.02091 | 0.00949 | 4.8578 | 0.0275 | 1.021 | 1.002–1.040 |
| MEP, % predicted | −0.02138 | 0.01111 | 3.7003 | 0.0544 | 0.979 | 0.958–1.000 |
| Absolute survival |
||||||
| Tw Pdi, cm H2O | −0.03754 | 0.01201 | 9.7724 | 0.0018 | 0.963 | 0.941–0.986 |
| MEP, cm H2O | −0.01529 | 0.00570 | 7.1953 | 0.0073 | 0.985 | 0.974–0.996 |
Definition of abbreviations: CI = confidence interval; MEP = maximal static expiratory mouth pressure; Sn Pdi = sniff trans-diaphragmatic pressure; Sn Pes = sniff esophageal pressure; Tw Pdi = twitch trans-diaphragmatic pressure.