Description of the study cohort at baseline (total N=919)
| Age (years) | 51 (40,60) |
| Male | 199/919 (21.7) |
| Female | 720/919 (78.3) |
| Disease duration (months)* | 42.5 (17,104) |
| Short disease duration ≤36 months* | 389/854 (45.6) |
| Raynaud's phenomenon | 898/919 (97.7) |
| Puffy fingers | 235/390 (60.3) |
| Digital ulcers (ever) | 396/914 (43.3) |
| Active digital ulcers | 84/394 (21.3) |
| mRSS | 16 (11,23) |
| Organ involvement | |
| Musculoskeletal | |
| Synovitis† | 196/915 (21.4) |
| Joint contractures | 458/916 (50.0) |
| Tendon friction rubs | 185/914 (20.2) |
| Muscle weakness | 294/915 (32.1) |
| Cardiopulmonary | |
| Dyspnoea (NYHA) | |
| Stage I | 210/369 (56.9) |
| Stage II | 118/369 (32.0) |
| Stage III | 37/369 (10.0) |
| Stage IV | 4/369 (1.1) |
| Conduction blocks | 109/877 (12.4) |
| Diastolic dysfunction | 165/864 (19.1) |
| LVEF <45% | 6/318 (1.9) |
| Pulmonary hypertension by Echo | 167/868 (19.2) |
| Lung fibrosis on chest X-ray | 389/849 (45.8) |
| Lung fibrosis on HRCT | 163/287 (56.8) |
| FVC <80% | 127/362 (35.1) |
| TLC <80% | 80/245 (32.7) |
| DLCO <70% | 357/621 (57.5) |
| Gastrointestinal | |
| Oesophageal symptoms | 625/917 (68.2) |
| Stomach symptoms | 257/916 (28.1) |
| Intestinal symptoms | 222/917 (24.2) |
| Renal crisis | 23/915 (2.5) |
| Laboratory markers | |
| ANA | 859/908 (94.6) |
| ACA | 76/872 (8.7) |
| Anti-Scl70 | 524/886 (59.1) |
| Anti-U1RNP | 16/285 (5.6) |
| Anti-RNA polymerase III | 18/215 (8.4) |
| CK elevation | 112/879 (12.7) |
| Proteinuria | 74/887 (8.3) |
| ESR>25 mm/1 h | 134/368 (36.4) |
| CRP elevation | 107/374 (28.6) |
| Active disease (VAI >3)12 | 146/337 (43.3) |
| Immunosuppressive treatment | 334/436 (76.6) |
For nominal variables, the absolute and relative frequencies are shown: n/total valid cases (%). Continuous variables are described as median and 1st, 3rd quartiles (Q1, Q3).
*Disease duration was calculated as difference between the date of the baseline visit and the date of the first non-Raynaud's symptom of the disease, as reported by the patients.
†Joint synovitis was defined as swelling of the joints as judged by the treating physician.
ACA, anticentromere antibodies; ANA, antinuclear antibodies; Anti-Scl70 antibodies, antitopoisomerase I antibodies; CK, creatine kinase; CRP, C reactive protein; DLCO, diffusing capacity of the lung for carbon monoxide; Echo, echocardiography; ESR, erythrocyte sedimentation rate; FVC, forced vital capacity; HRCT, high resolution computer tomography; LVEF, left ventricular ejection fraction; mRSS, modified Rodnan skin score; NYHA, New York Heart Association; RNP, ribonucleoprotein; TLC, total lung capacity; VAI, Valentini Activity Index.