Table 3.
Univariate and multivariate Cox proportional hazards analysis of risk factors for acute exacerbation or all-cause mortality in the rheumatoid arthritis-associated interstitial lung disease (RA-ILD) cohort.
| Variable | Univariate analysis | Multivariate analysis | ||
|---|---|---|---|---|
| HR (95% CI) | p-Value | HR (95% CI) | p-Value | |
| Gender | ||||
| Female | 1 | 0.832 | 1 | 0.539 |
| Male | 1.089 (0.485–2.445) | 0.507 (0.058–4.417) | ||
| Age at inclusion (years) | ||||
| ≤50 | 1 | 0.269 | 1 | 0.432 |
| >50 | 1.978 (0.589–6.639) | 1.349 (0.483–5.420) | ||
| Age at onset of RA (years) | ||||
| ≤50 | 1 | 0.041 | 1 | 0.171 |
| >50 | 2.916 (1.037–8.202) | 5.247 (0.489–56.363) | ||
| RA duration (years) | ||||
| ≤10 | 1 | 0.06 | 1 | 0.882 |
| >10 | 0.245 (0.054–1.101) | 1.158 (0.166–8.073) | ||
| Ever smoker | ||||
| Yes | 1 | 0.39 | 1 | 0.409 |
| No | 0.39 (0.572–4.075) | 0.627 (0.207–1.899) | ||
| ACPA titer | ||||
| ≤500 | 1 | 0.033 | 1 | 0.528 |
| >500 | 3.949 (1.119–13.932) | 0.722 (0.262–1.989) | ||
| UIP pattern on HRCT | ||||
| No | 1 | 0.015 | 1 | 0.297 |
| Yes | 4.115 (1.196–14.164) | 1.693 (0.630–4.551) | ||
| DLCO (% of predicted value) | ||||
| >55 | 1 | 0.620 | 1 | 0.830 |
| ≤55 | 0.783 (0.295–2.081) | 1.101 (0.458–2.644) | ||
| MUC5B mutation | ||||
| WT | 1 | 0.043 | 1 | 0.065 |
| MT | 2.308 (1.006–5.292) | 2.312 (0.951–5.620) | ||
HR – hazard ratio; CI – confidence interval; WT – wild-type; MT – mutant-type; RA – rheumatoid arthritis; ILD – interstitial lung disease; ACPA – anti-citrullinated protein antibody; NSIP – non-specific interstitial pneumonia; UIP – usual interstitial pneumonia; DLCO – diffusion capacity for carbon monoxide; HRCT – high-resolution computed tomography.