Table 1. Baseline patient characteristics.
| RA ACR/EULAR 2010 | P-value | |||
| RA (all) (n = 69) | RA-RA (n = 56) | UA-RA (n = 13) | ||
| Age (yrs) | 48 (169) | 47 (18) | 57 (18) | 0.03 |
| Dis.dur. (mo) | 4 (6) | 5 (7) | 4 (4) | 0.16 |
| Female, n (%) | 49 (71%) | 40 (71%) | 9 (69%) | 0.89 |
| VAS global disease activity (0–100 mm) | 50 (42) | 56 (39) | 43 (49) | 0.14 |
| VAS pain (0–100 mm) | 51 (50) | 63 (46) | 30 (38) | 0.04 |
| MS (min) | 30 (55) | 45 (75) | 1 (15) | 0.17 |
| ESR (mm/h) | 27 (30) | 29 (31) | 14 (32) | 0.09 |
| CRP (mg/L) | 11 (24) | 12 (30) | 5 (16) | 0.02 |
| TJC68 (n) | 9 (16) | 12 (18) | 1 (2) | <0.001 |
| SJC66 (n) | 5 (8) | 7 (7) | 1 (1) | <0.001 |
| RF pos, n (%) | 24 (35%) | 21 (38%) | 3 (20%) | 0.05 |
| ACPA pos, n (%) | 23 (30%) | 23 (41%) | 0 (0%) | 0.008 |
Data are presented as median (interquartile range) or number (n [%]), as appropriate. Baseline characteristics were compared between the two diagnostic groups using a Mann-Whitney U test or a Chi2-test (sex, RF pos, ACPA pos). A P-value of <0.05 was considered statistically significant (bold). RA = rheumatoid arthritis; RA (all) = all patients with RA diagnosis after 2 years of follow up; RA−RA = RA at baseline and follow up; UA−RA = initially UA, but definitive diagnosis of RA at follow up; dis.dur. = disease duration; VAS = visual analog scale; MS = morning stiffness; ESR = erythrocyte sedimentation rate; CRP = C-reactive protein; TJC68 = tender joint count; SJC66 = swollen joint count; RF = IgM rheumatoid factor; ACPA = anti-citrullinated protein antibodies; pos = serum positive.