Risk factors for AE occurrence according to univariate cox hazard analysis
| HR | 95% CI | p Value | |
|---|---|---|---|
| Age at RA diagnosis | 1.03 | 0.97 to 1.10 | 0.35 |
| Age at ILD diagnosis | 1.11 | 1.02 to 1.21 | 0.01* |
| Sex, male | 0.90 | 0.49 to 1.69 | 0.73 |
| Smoking habit, yes | 1.60 | 0.81 to 4.10 | 0.19 |
| UIP pattern on HRCT, yes | 1.95 | 1.07 to 3.63 | 0.03* |
| PaO2 at ILD diagnosis | 1.05 | 0.98 to 1.12 | 0.14 |
| %FVC at ILD diagnosis | 1.02 | 0.99 to 1.06 | 0.24 |
| Treatment for RA at final visit† or AE onset‡ | |||
| Corticosteroids | 0.97 | 0.53 to 1.92 | 0.94 |
| Immunosuppressant except for MTX | 0.76 | 0.35 to 1.41 | 0.39 |
| MTX | 3.04 | 1.62 to 6.02 | 0.001* |
| Other drugs | 0.98 | 0.50 to 1.80 | 0.96 |
*p<0.05.
†In non-AE group.
‡In AE group.
AE, acute exacerbation; %FVC, predicted forced vital capacity; HRCT, high resolution CT; ILD, interstitial lung disease; MTX, methotrexate; PaO2, arterial oxygen pressure; RA, rheumatoid arthritis; UIP, usual interstitial pneumonia.