Table 4. Cox proportional hazards model results for evaluating the risk of mortality in patients with idiopathic pulmonary fibrosis (n = 33).
| Univariate analysis | Hazards ratio | 95%CI | p-value | ||
| Age, years | 1.01 | 0.95 | – | 1.07 | 0.75 |
| Male gender | 0.38 | 0.12 | – | 1.20 | 0.099 |
| BMI, kg/m2 | 0.85 | 0.74 | – | 0.97 | 0.01 |
| Ever smoker | 0.96 | 0.34 | – | 2.68 | 0.94 |
| Pulmonary hypertension | 0.91 | 0.20 | – | 4.06 | 0.90 |
| History of acute exacerbation | 3.38 | 0.91 | – | 12.58 | 0.07 |
| History of pneumothorax | 1.94 | 0.61 | – | 6.15 | 0.26 |
| %FVC, per 10%* | 0.78 | 0.57 | – | 1.08 | 0.14 |
| %DLCO, per 10%† | 0.48 | 0.27 | – | 0.84 | 0.01 |
| 6MWD, per 10m | 0.96 | 0.93 | – | 1.00 | 0.08 |
| Oxygen flow ≥2L/min at 6MWT | 2.13 | 0.79 | – | 5.77 | 0.14 |
| GAP stage II or III | 2.70 | 0.76 | – | 9.66 | 0.13 |
| Multivariate analysis | Hazards ratio | 95%CI | p-value | ||
| Male gender | – | – | – | ||
| BMI, kg/m2 | 0.83 | 0.72 | – | 0.95 | < 0.01 |
| History of acute exacerbation | 4.50 | 1.15 | – | 17.66 | 0.03 |
| 6MWD, m | – | – | – | ||
CI, confidence interval; BMI, body mass index; ILD, interstitial lung disease; %FVC, percent predicted forced vital capacity; %DLCO, percent predicted diffusing capacity of the lung for carbon monoxide; 6MWD, 6-min walking distance; 6MWT, the 6-min walk test; GAP stage, gender-age-physiology stage.
*n = 32
†n = 28.