Table 2.
Univariate analysis
| Variable | HR | 95% CI | P-value |
|---|---|---|---|
| Age (5-year increase) | 1.23 | 1.18–1.28 | <0.0001 |
| Female | 0.78 | 0.66–0.92 | 0.003 |
| IC/TLC ≤25% | 2.39 | 2.03–2.82 | <0.0001 |
| FEV1 mild vs moderate | 0.48 | 0.35–0.65 | <0.0001 |
| FEV1 severe vs moderate | 1.38 | 1.11–1.70 | 0.003 |
| FEV1 very severe vs moderate | 1.81 | 1.46–2.23 | <0.0001 |
| BMI <20 vs BMI 20 to <25 | 1.22 | 0.99–1.51 | 0.068 |
| BMI ≥25 vs BMI 20 to <25 | 0.81 | 0.67–0.97 | 0.022 |
| DLCO <22% | 2.08 | 1.68–2.57 | <0.0001 |
| IC ≥80% | 0.48 | 0.41–0.57 | <0.0001 |
Abbreviations: BMI, body mass index; CI, confidence interval; DLCO, diffusing capacity of the lungs for carbon monoxide; FEV1, forced expiratory volume in 1 second; HR, hazard ratio; IC, inspiratory capacity; TLC, total lung capacity.