Table 2.
Baseline characteristics and 5-year outcome according to baseline and 5-year anti-CCP status
| Anti-CCP negative at baseline | Anti-CCP positive at baseline | |||||
|---|---|---|---|---|---|---|
| 5-year anti-CCP status |
Anti-CCP negative (n = 436, 98%) CCP-/- |
Anti-CCP positive (n = 9, 2%) CCP-/+ |
P value | Anti-CCP negative (n = 9, 4.6%) CCP+/- |
Anti-CCP positive (n = 186, 95.4%) CCP+/+ |
P value |
| Baseline characteristic | ||||||
| Age (n = 640) | 51.9 (40.7, 63.1) | 47.1 (42.8, 57.1) | 0.39 | 53.4 (50.1, 58.5) | 56.1 (48.1, 65.0) | 0.46 |
| Female (n = 640) | 293 (67%) | 7 (78%) | 0.72 | 5 (56%) | 114 (61%) | 0.74 |
| Symptom duration (n = 596) | 4.9 (2.1, 10.4) | 3.6 (2.5, 10.1) | 0.77 | 4.8 (3.1, 6.1) | 5.3 (2.9, 10.9) | 0.82 |
| RF +ve (n = 640) | 43 (9.8%) | 3 (33%) | 0.06 | 6 (67%) | 130 (70%) | 1.0 |
| Anti-CCP titer (n = 596) | 0.8 (0.5, 1.4) | 1.5 (1.4, 3.8) | 0.0004 | 16.2 (13.0, 41.6) | 66.8 (32, 101) | 0.005 |
| SE - 1 or 2 copies (n = 593) | 213 (53%) | 7 (100%) | 0.017 | 7 (88%) | 138 (78%) | 1.0 |
| HAQ (n = 639) | 0.6 (0.3, 1.1) | 1.1 (0.6, 1.3) | 0.13 | 0.8 (0.4, 1.5) | 0.9 (0.4, 1.6) | 0.88 |
| CRP (n = 591) | 3 (0, 11) | 4 (1, 14) | 0.73 | 10 (6, 16) | 11 (4, 26) | 0.83 |
| Swollen joints (n = 640) | 6 (2, 12) | 11 (5, 13) | 0.12 | 5 (2, 10) | 8 (4, 17) | 0.22 |
| Tender joints (n = 640) | 7 (2, 16) | 15 (6, 24) | 0.11 | 7 (5, 8) | 9 (4, 16) | 0.24 |
| DAS28 (n = 591) | 3.7 (2.7, 4.8) | 5.1 (3.2, 5.5) | 0.22 | 4.0 (3.2, 4.5) | 4.5 (3.5, 5.4) | 0.30 |
| Current smoker (n = 640) | 102 (23%) | 2 (22%) | 1.0 | 0 (0) | 56 (30%) | 0.06 |
| Fulfils ACR criteria (n = 640) | 168 (39%) | 4 (44%) | 0.74 | 6 (67%) | 135 (73%) | 0.71 |
| Outcome year 5 | ||||||
| Erosions (n = 523) | 95 (27%) | 6 (85%) | 0.002 | 6 (75%) | 125 (80%) | 0.66 |
| Larsen score (n = 521) | 2 (0, 10) | 35 (19, 71) | 0.001 | 28 (5, 44) | 28 (11, 43) | 0.80 |
| HAQ (n = 639) | 0.6 (0, 1.4) | 1.6 (0.1, 2.1) | 0.24 | 1.1 (0.4, 1.8) | 1.1 (0.5, 2) | 0.40 |
| Swollen joints (n = 475) | 1 (0, 3) | 2 (1, 5) | 0.07 | 1 (0, 2) | 3 (0, 8) | 0.04 |
| Tender joints (n = 475) | 1 (0, 6) | 3 (0, 11) | 0.67 | 2 (0, 4) | 3(0, 11) | 0.20 |
| DAS28 (n = 463) | 2.2 (1.4, 3.1) | 2.9 (1.6, 4.2) | 0.25 | 1.7 (1.2, 3.4) | 3.3 (2.4, 4.4) | 0.03 |
| DMARD received (n = 639) | 124 (29%) | 8 (89%) | < 0.0001 | 7 (78%) | 162 (87%) | 0.34 |
| Fulfils ACR criteria (n = 639) | 268 (62%) | 8 (89%) | 0.16 | 8 (89%) | 179 (96%) | 0.32 |
Continuous variables expressed as median (interquartile range) and compared by using the Mann-Whitney U test. Categoric variables expressed as number (percentage) and compared by using the Fisher Exact test. ACR, American College of Rheumatology criteria for rheumatoid arthritis; CRP, C-reactive protein; DAS28, disease activity score in 28 joints; DMARD, disease-modifying antirheumatic drug;
HAQ, Health Assessment Questionnaire; RF, rheumatoid factor.