Characteristics | Total | Seropositive | Seronegative | Missing ACPA, RF− | p | p Adjusted for Covariates |
---|---|---|---|---|---|---|
Baseline | ||||||
No. patients, n (%) | 1998 | 1276 (58.2) | 497 (22.7) | 225 (10.3) | N/A | |
Age, yrs, range | 16–92 | 17–88 | 17–88 | 17–88 | N/A | |
Age | 53.04 ± 0.34 | 51.63 ± 0.44 | 54.04 ± 0.67 | 55.58 ± 0.80 | 0.000009* | |
RF serology, n (%) | 1110 (50.7) | 813 (37.1) | 268 (12.2) | N/A | ||
ACPA serology, n (%) | 736 (33.6) | 724 (33.0) | 731 (33.4) | N/A | ||
Female, n (%) | 1445 (72.6) | 958 (75.5) | 336 (67.6) | 151 (67.4) | 0.0007* | |
Symptom duration, mos | 6.04 ± 0.08 | 6.24 ± 0.11 | 5.89 ± 0.18 | 5.26 ± 0.21 | 0.0008* | |
Smoking status, n (%) | 0.003* | |||||
Current smoker | 363 (18.3) | 256 (20.2) | 82 (16.7) | 25 (11.2) | ||
Ex-smoker | 736 (37.1) | 480 (37.8) | 172 (35.0) | 84 (37.7) | ||
Never | 885 (44.6) | 533 (42.0) | 238 (48.4) | 114 (51.1) | ||
ESR | 26.85 ± 0.53 | 28.07 ± 0.66 | 24.85 ±1.08 | 26.57 ± 1.46 | 0.01* | 0.002* |
CRP | 14.04 ± 0.41 | 14.20 ± 0.52 | 13.67 ± 0.83 | 13.98 ± 1.19 | 0.86 | 0.35 |
SJC28 | 7.23 ± 0.14 | 7.05 ± 0.17 | 7.44 ± 0.30 | 7.74 ± 0.38 | 0.19 | 0.29 |
DAS28 | 4.89 ± 0.04 | 4.92 ± 0.05 | 4.81 ± 0.07 | 4.90 ± 0.10 | 0.45 | 0.63 |
HAQ-DI | 1.00 ± 0.02 | 1.01 ± 0.02 | 0.98 ± 0.03 | 0.97 ± 0.05 | 0.57 | 0.69 |
Meets 2010 ACR/EULAR classification criteria for RA, n (%) | 1569 (78.8) | 1138 (89.7) | 293 (59.0) | 138 (61.6) | 0.000001* | 0.000001* |
MTX, n (%) | 1296 (64.9) | 889 (69.7) | 283 (56.9) | 124 (55.1) | 0.000001* | 0.000001* |
No. DMARD | 1.31 ± 0.02 | 1.41 ± 0.02 | 1.17 ± 0.04 | 1.05 ± 0.05 | 0.000001* | 0.000001* |
No. DMARD, range | 0–4 | 0–4 | 0–4 | 0–4 | N/A | |
Corticosteroid, n (%) | 966 (48.3) | 614 (48.1) | 234 (47.1) | 118 (52.4) | 0.40 | 0.34 |
PGA | 5.71 ± 0.07 | 5.73 ± 0.09 | 5.77 ± 0.13 | 5.48 ± 0.19 | 0.46 | 0.0009* |
PtGA | 4.63 ± 0.06 | 4.77 ± 0.07 | 4.35 ± 0.11 | 4.51 ± 0.17 | 0.004* | 0.66 |
3 mos | ||||||
No. patients, n (%) | 1743 | 1062 (60.9) | 359 (20.6) | 171 (9.8) | N/A | |
ESR | 18.70 ± 0.48 | 19.65 ± 0.60 | 16.63 ± 0.91 | 18.54 ± 0.15 | 0.03* | 0.086 |
CRP | 7.09 ± 0.33 | 6.98 ± 0.41 | 7.65 ± 0.73 | 6.60 ± 0.74 | 0.54 | 0.42 |
SJC28 | 3.46 ± 0.11 | 3.44 ± 0.14 | 3.51 ± 0.21 | 3.42 ± 0.25 | 0.95 | 0.33 |
DAS28 | 3.55 ± 0.04 | 3.51 ± 0.05 | 3.60 ± 0.09 | 3.70 ± 0.13 | 0.33 | 0.32 |
Change in DAS28 | −1.35 ± 0.05 | −1.38 ± 0.05 | −1.21 ± 0.10 | −1.41 ± 0.15 | 0.29 | 0.07 |
Proportion in DAS28, n (%) | 343 (28.2) | 248 (29.8) | 62 (24.3) | 33 (25.2) | 0.17 | 0.06 |
HAQ-DI | 0.63 ± 0.16 | 0.61 ± 0.02 | 0.69 ± 0.04 | 0.67 ± 0.05 | 0.12 | 0.02* |
MTX, n (%) | 1194 (75.0) | 830 (78.2) | 250 (69.6) | 114 (66.7) | 0.0002* | 0.0002* |
No. DMARD | 1.60 ± 0.02 | 1.67 ± 0.03 | 1.51 ± 0.05 | 1.36 ± 0.06 | 0.00002* | 0.0009* |
Corticosteroid, n (%) | 559 (35.1) | 370 (34.8) | 133 (37.0) | 56 (32.7) | 0.59 | 0.45 |
PGA | 2.56 ± 0.06 | 2.57 ± 0.07 | 2.50 ± 0.12 | 2.59 ± 0.18 | 0.87 | 0.96 |
PtGA | 3.71 ± 0.07 | 3.56 ± 0.09 | 4.07 ± 0.15 | 3.84 ± 0.22 | 0.01* | 0.005* |
↵* p < 0.05. RF: rheumatoid factor; ACPA: anticitrullinated protein antibodies; DAS28: 28-joint Disease Activity Score; SEM: standard error of the mean; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; SJC28: swollen joint count at 28 joints; ACR: American College of Rheumatology; HAQ-DI: Health Assessment Questionnaire-Disability Index; EULAR: European League Against Rheumatism; MTX: methotrexate; DMARD: disease-modifying antirheumatic drugs; PGA: physician’s global assessment; PtGA: patient’s global assessment; N/A: not applicable.