Table 3.
Univariate Cox-proportional hazards analysis for predicting acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF).
| Variables | HR | 95%CI | p Value |
|---|---|---|---|
| Age (continuous) | 0.99 | 0.94–1.05 | 0.73 |
| Male sex | 0.87 | 0.29–2.57 | 0.80 |
| Positive smoking history | 0.97 | 0.36–2.64 | 0.96 |
| Pack-year | 0.99 | 0.97–1.01 | 0.19 |
| Japanese Ethnicity | 3.17 | 1.07–9.37 | 0.037 |
| %VC ≥ 74% (median) | 0.37 | 0.15–0.92 | 0.031 |
| %DLco ≥ 44% (median) | 0.51 | 0.21–1.23 | 0.13 |
| Use of corticosteroid | 1.76 | 0.76–4.08 | 0.19 |
| Use of immunosuppressive agent | 1.03 | 0.35–3.06 | 0.96 |
| Use of pirfenidone | 0.52 | 0.16–1.77 | 0.30 |
| GGO > 4.5% | 3.27 | 1.42–7.55 | 0.0055 |
| Fibrosis > 18.7% | 2.93 | 1.26–6.79 | 0.012 |
| Emphysema > 8.3% | 1.67 | 0.56–4.92 | 0.36 |
| Zones with traction bronchiectasis >5 (n) | 2.29 | 0.98–5.34 | 0.055 |
Statistical significance was tested by the Cox-proportional hazards model. AE-IPF, acute exacerbation of idiopathic pulmonary fibrosis: HR, hazard ratio: VC, forced vital capacity: DLCO, diffusing capacity of carbon monoxide: GGO, ground glass opacity: CI, confidence interval.