Table 2.
Baseline characteristics of patients with systemic sclerosis with vs. without clinically meaningful %-predicted forced vital capacity (FVC) worsening
| Full Analytic Cohort (N=138) |
Radiographic ILD present (N=100) |
|||||
|---|---|---|---|---|---|---|
| Mean (SD) or N (%) | No FVC decline (N =89) |
FVC decline ≥5 (N=49) |
p-value | No FVC decline (N=61) |
FVC decline ≥5 (N=39) |
p-value |
| Age at time of HRCT, years | 49.2 (11.9) | 51.7 (9.4) | 0.179 | 48.6 (12.4) | 51.0 (10.1) | 0.281 |
| Sex, women | 78 (87.6) | 38 (77.6) | 0.191 | 52 (85.2) | 30 (76.9) | 0.430 |
| Race, white | 67 (75.3) | 37 (75.5) | 1.000 | 42 (68.9) | 28 (71.8) | 0.929 |
| Smoker, current or former | 32 (36.0) | 20 (40.8) | 0.704 | 20 (32.8) | 17 (43.6) | 0.379 |
| Gastrointestinal symptoms, present | 66 (74.2) | 36 (73.5) | 1.000 | 44 (72.1) | 30 (76.9) | 0.765 |
| Pulmonary symptoms, present | 53 (59.6) | 30 (61.2) | 0.992 | 38 (62.3) | 28 (71.8) | 0.446 |
| Proton pump inhibition, current | 53 (59.6) | 28 (57.1) | 0.925 | 36 (59.0) | 24 (61.5) | 0.967 |
| SSc disease subtype, diffuse | 42 (47.2) | 22 (44.9) | 0.936 | 36 (59.0) | 18 (46.2) | 0.292 |
| SSc disease duration, years* | 5.6 (7.5) | 5.8 (8.1) | 0.887 | 4.1 (5.1) | 5.5 (6.9) | 0.268 |
| Anti-Scl-70, positive | 25 (28.1) | 25 (51.0) | 0.013 | 24 (39.3) | 24 (61.5) | 0.05 |
| Anti-centromere, positive | 17 (19.1) | 7 (14.3) | 0.632 | 4 (6.6) | 2 (5.1) | 1.000 |
| Anti-RNA polymerase III, positive | 26 (29.9) | 8 (16.7) | 0.137 | 19 (31.7) | 5 (12.8) | 0.058 |
| Erythrocyte sedimentation rate | 24 (25.1) | 23 (17.8) | 0.820 | 20 (18.1) | 25 (19.2) | 0.240 |
| Modified Rodnan skin score | 11.9 (9.7) | 10.5 (7.5) | 0.344 | 13.8 (10.1) | 10.9 (7.8) | 0.116 |
| Medications, any use | 41 (46.1) | 23 (46.9) | 1.000 | 32 (52.5) | 20 (51.3) | 1.000 |
| Cyclophosphamide | 4 (4.5) | 2 (4.1) | 1.000 | 4 (6.6) | 2 (5.1) | 1.000 |
| Mycophenolate mofetil | 18 (20.2) | 13 (26.5) | 0.525 | 15 (24.6) | 12 (30.8) | 0.654 |
| Prednisone | 24 (27.0) | 11 (22.4) | 0.705 | 18 (29.5) | 9 (23.1) | 0.634 |
| Pulmonary hypertension present among those with RHC (N = 56) | 8 (26.7) | 11 (42.3) | 0.342 | 6 (28.6) | 11 (47.8) | 0.317 |
| Radiographic ILD, present | 61 (68.5) | 39 (79.6) | 0.233 | 61 (100.0) | 39 (100.0) | NA |
| FVC %-predicted, baseline | 77 (16.8) | 79 (16.8) | 0.714 | 74 (17.9) | 75 (16.6) | 0.793 |
| DLCO %-predicted, baseline | 60 (19.6) | 59 (21.8) | 0.741 | 59 (20.2) | 54 (19.3) | 0.202 |
| Digital ulcers, present | 38 (42.7) | 14 (28.6) | 0.146 | 30 (49.2) | 10 (25.6) | 0.033 |
| Widest esophageal diameter | 17.2 (7.9) | 18.3 (8.6) | 0.425 | 18.6 (7.6) | 18.6 (8.3) | 0.987 |
SSc disease duration defined as the interval between first non-Raynaud SSc symptom and baseline HRCT date. Widest esophageal diameter measured in mm; HRCT=high-resolution computed tomography of the chest; SSc=systemic sclerosis; ILD=interstitial lung disease; PAH=pulmonary arterial hypertension; RHC=right heart catheterization; FVC=forced vital capacity; DLCO=diffusing capacity of the lungs for carbon monoxide (adjusted for hemoglobin). Pulmonary and gastrointestinal symptoms defined as positive pulmonary and/or gastrointestinal review of systems in an outpatient rheumatology clinic note within one year of HRCT date.