Baseline characteristics of early arthritis patients classified as RA, SpA or UA after 2 years of follow-up.

IgM-RF = IgM rheumatoid factor; anti-CCP = anti-cyclic citrullinated peptide antibodies; ESR = erythrocyte sedimentation rate; CRP = C-reactive protein; VAS = visual analogue scale (rang 0–100 mm); 68 TJC = tender joint count of 68 joints; 66 SJC = swollen joint count of 66 joints; * missing for 1 patient; ** missing for 2 patients; SD: standard deviation; IQR: interquartile range; NSAID: non steroidal anti-inflammatory drug Baseline characteristics of early arthritis patients classified as RA, SpA or UA after 2 years of follow-up.