Table 3. Risk Factors at Baseline for Progressive Lung Function Decline in Patients with Rheumatoid Arthritis associated Interstitial Lung Disease.
| DLCO < 40% predicted | FVC < 50% | |||
|---|---|---|---|---|
| Risk Factor | Hazard ratio (95% CI) | P-value | Hazard ratio (95% CI) | P-value |
| Age * | 1.26 (0.79, 1.98) | 0.33 | 1.06 (0.61, 1.82) | 0.84 |
| Male sex | 1.75 (0.74, 4.10) | 0.20 | 0.98 (0.33, 2.92) | 0.97 |
| Ever smoker | 0.35 (0.14, 0.85) | 0.021 | 0.45 (0.15, 1.47) | 0.20 |
| Emphysema | 1.34 (0.39, 4.57) | 0.64 | 0.52 (0.07, 4.04) | 0.53 |
| RF or ACPA positive | 2.61 (0.35, 19.57) | 0.35 | 0.51 (0.11, 2.33) | 0.38 |
| ESR (mm/1hr) * | 1.04 (0.86, 1.25) | 0.71 | 0.83 (0.58, 1.17) | 0.28 |
| CRP (mg/L) * | 0.98 (0.79, 1.21) | 0.82 | 0.74 (0.37, 1.49) | 0.40 |
| Rheumatoid nodules | 1.00 (0.40, 2.53) | 0.99 | -- | 0.99 |
| Severe extra-articular manifestations | -- | 0.99 | -- | 0.99 |
| UIP vs NSIP | 3.29 (1.28, 8.41) | 0.013 | 0.86 (0.27, 2.73) | 0.79 |
| FVC percent predicted† | 1.25 (0.97, 1.64) | 0.087 | 2.38 (1.37, 4.17) | 0.002 |
| DLCO percent predicted† | 3.74 (1.96, 7.14) | <0.001 | 1.67 (1.16, 2.44) | 0.005 |
| Pulmonary hypertension** | 2.65 (0.93, 7.58) | 0.069 | 1.26 (0.32, 5.04) | 0.74 |
| Ever having had a TTE†† | 1.56 (0.48, 5.10) | 0.46 | 1.49 (0.40, 5.61) | 0.55 |
| Years from RA to ILD Dx* | 1.35 (0.74, 2.46) | 0.32 | 1.14 (0.56, 2.34) | 0.72 |
| FVC rate of change*** | 3.42 (1.61, 7.24) | 0.001 | ||
| FVC rate of decrease ≥ 10% | 7.53 (1.81, 31.27) | 0.005 | ||
| DLCO rate of change*** | 1.72 (1.07, 2.74) | 0.024 | ||
| DLCO rate of decrease ≥ 15% | 1.52 (0.19, 12.40) | 0.69 | ||
| SSZ/HCQ alonex | 1.0 (Reference) | 1.0 (Reference) | ||
| MTX/LEF alone | 1.42 (0.15, 13.76) | 0.76 | -- | 0.99 |
| TNFi (with anyxx) | 1.60 (0.18, 14.31) | 0.68 | 1.04 (0.09, 11.72) | 0.97 |
| non-TNFi biologic (with any) | -- | 0.99 | 1.67 (0.14, 19.60) | 0.68 |
| Prednisone ≤ 10 mg per day alonex | 2.60 (0.26, 25.77) | 0.41 | 1.78 (0.11, 29.00) | 0.69 |
| Prednisone > 10 mg per day (with anyxx) | 5.32 (0.60, 47.11) | 0.13 | 15.04 (1.50, 150.8) | 0.021 |
| Other DMARD or combination | 1.57 (0.16, 15.45) | 0.70 | 0.60 (0.04, 10.20) | 0.73 |
| No therapy | 2.33 (0.24, 22.56) | 0.46 | 1.42 (0.09, 23.14) | 0.81 |
All models adjusted for age at ILD diagnosis and sex.
Per 10-unit increase.
Per 10-unit decrease
Developed pulmonary hypertension during follow-up.
Per 10% decrease in first 6 months of follow-up.
Having TTE related to suspicion for pulmonary hypertension, not causation.
Alone: without other antirheumatic drug or glucocorticoid.
with any: alone or in combination with any other antirheumatic drug. Patients taking both TNFi (or non-TNFi) biologic and prednisone >10mg are in the TNFi (or non-TNFi) biologic group.
Abbreviations: Anti-citrullinated protein antibody (ACPA), C - reactive protein (CRP), diagnosis (Dx), diffusing capacity for carbon monoxide (DLCO), erythrocyte sedimentation rate (ESR), forced vital capacity (FVC), nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), rheumatoid factor (RF), transthoracic echo (TTE), sulfasalazine (SSZ), hydroxychloroquine (HCQ), methotrexate (MTX), leflunomide (LEF), tumor necrosis factor inhibitor (TNFi), rituximab and abatacept (non TNFi), disease modifying anti-rheumatic drug (DMARD)