Table 3.
Analysis of prognostic factors in patients with polymyositis/dermatomyositis-related interstitial lung disease using the Cox proportional hazard model
| Variables | Unadjusted HR | 95% CI | P | Age-adjusted and gender-adjusted HR | 95% CI | P |
|---|---|---|---|---|---|---|
| Age (per 1 year increase) | 1.01 | 0.96–1.07 | 0.62 | − | − | − |
| Male | 1.93 | 0.61–6.09 | 0.26 | − | − | − |
| Current or former smoker | 2.27 | 0.71–7.23 | 0.17 | 1.96 | 0.47–8.24 | 0.36 |
| CADM | 0.37 | 0.10–1.38 | 0.14 | 0.41 | 0.11–1.60 | 0.12 |
| Fever | 4.29 | 1.27–14.50 | 0.02 | 4.68 | 1.36–16.10 | 0.01 |
| Cough | 0.65 | 0.20–2.16 | 0.48 | 0.76 | 0.22–2.67 | 0.67 |
| Dyspnea | 2.30 | 0.69–7.64 | 0.18 | 2.65 | 0.78–9.03 | 0.12 |
| Muscle pain or weakness | 2.69 | 0.73–9.97 | 0.14 | 2.44 | 0.63–9.48 | 0.20 |
| Rash typical for DM | 0.40 | 0.09–1.85 | 0.24 | 0.47 | 0.10–2.27 | 0.35 |
| Raynaud’s phenomenon | 2.99 | 0.81–11.13 | 0.10 | 3.03 | 0.72–12.84 | 0.13 |
| Arthralgia | 1.54 | 0.49–4.90 | 0.46 | 1.39 | 0.42–4.59 | 0.59 |
| CK (per 10 IU/mL increase) | 1.00 | 0.995–1.01 | 0.97 | 1.00 | 0.994–1.006 | 0.96 |
| CRP (per 1 mg/dL increase) | 1.13 | 0.91–1.41 | 0.27 | 1.13 | 0.91–1.41 | 0.27 |
| KL-6 (per 100 U/mL increase) | 1.06 | 0.998–1.12 | 0.06 | 1.05 | 0.995–1.12 | 0.07 |
| Ferritin (per 100 ng/mL increase) | 1.02 | 1.01–1.04 | 0.01 | 1.03 | 1.01–1.05 | 0.01 |
| Soluble CD163 (per 100 ng/mL increase) | 1.22 | 1.09–1.36 | 0.001 | 1.27 | 1.11–1.45 | <0.001 |
| PaO2 on room air (per 10 Torr increase) | 0.48 | 0.30–0.76 | 0.002 | 0.48 | 0.28–0.81 | 0.01 |
| Anti-MDA5-positive | 2.60 | 0.81–8.32 | 0.11 | 3.11 | 0.90–10.74 | 0.07 |
| Percent predicted FVC (per 10% increase) | 0.73 | 0.61–0.88 | 0.001 | 0.65 | 0.50–0.83 | 0.001 |
ARS aminoacyl-tRNA synthetase, CADM clinically amyopathic dermatomyositis, CI confidence interval, CK creatine kinase, CRP C-reactive protein, DM dermatomyositis, FVC forced vital capacity, HR hazard ratio, KL-6 Krebs von den Lungen-6, MDA5 melanoma differentiation-associated gene 5