Table 2. Comparison of clinical features and outcomes in the IORRA survey conducted in April 2016 between the patients whose debut joint was the foot or ankle (FOOT group) and patients whose debut joint was another joint (non-FOOT group).
| FOOT group (n = 2,164) |
non-FOOT group (n = 2,164) |
P | |
|---|---|---|---|
| Age, years | 62.6 ± 12.3 (22–91) | 62.6 ± 12.2 (21–92) | 0.98 |
| Age at onset, years | 46.3 ± 12.7 (16–86) | 46.4 ± 12.8 (16–84) | 0.84 |
| Disease duration, years | 16.3 ± 10.3 (0–58) | 16.2 ± 10.2 (0–57) | 0.82 |
| Female, no. (%) | 1,898 (87.7) | 1,836 (84.8) | 0.007 |
| Having any symptoms in the foot or ankle joints now, no. (%) | 1,529 (71.3)† | 800 (37.3)‡ | <2.2e-16 |
| Body weight, kg | 52.5 ± 9.5 (27–99) | 53.4 ± 9.8 (30–100) | 0.004 |
| DAS28 | 2.82 ± 1.1 (0.0–7.0) | 2.51 ± 0.95 (0.0–6.1) | <2.2e-16 |
| TJC28 | 0.7 ± 1.8 (0–24) | 0.5 ± 1.1 (0–12) | 1.8e-09 |
| SJC28 | 1.1 ± 2.1 (0–18) | 0.7 ± 1.6 (0–18) | 2.0e-13 |
| TJC45 | 1.1 ± 2.6 (0–24) | 0.6 ± 1.4 (0–16) | <2.2e-16 |
| SJC45 | 1.3 ± 2.5 (0–30) | 0.8 ± 1.7 (0–18) | 1.7e-15 |
| PVAS, mm | 25.8 ± 24.7 (0–100) | 17.5 ± 20.8 (0–100) | <2.2e-16 |
| GVAS, mm | 29.3 ± 24.9 (0–99) | 20.9 ± 21.9 (0–100) | <2.2e-16 |
| DVAS, mm | 10.4 ± 13.0 (0–83) | 7.3 ± 9.8 (0–82) | <2.2e-16 |
| CRP, mg/dL | 0.44 ± 0.92 (0.0–9.7) | 0.32 ± 0.80 (0.0–18.3) | 4.1e-06 |
| ESR, mm/h | 24.6 ± 19.3 (1.0–100.0) | 21.6 ± 16.8 (1.0–100.0) | 1.0e-07 |
| WBC, /μL | 6018.5 ± 1973.7 | 5798.2 ± 1948.1 | 0.0002 |
| (2170–16820) | (2000–39880) | ||
| RF, IU/mL | 118.5 ± 260.7 (3–7150) | 97.2 ± 217.1 (3–5544) | 0.004 |
| RF positivity, no (%) | 1,824 (77.2) | 2,178 (71.0) | 2.9e-07 |
| anti-CCP positivity, no (%) | 1,795 (86.3) | 2,218 (80.3) | 4.1e-08 |
| RF/anti-CCP double-positive, no (%) | 1,518 (73.5) | 1,795 (65.5) | 2.5e-09 |
| J-HAQ | 0.69 ± 0.76 (0–3) | 0.47 ± 0.66 (0–3) | <2.2e-16 |
| EQ-5D | 0.78 ± 0.18 (-0.1–1.0) | 0.85 ± 0.2 (0.1–1.0) | <2.2e-16 |
| NSAID use, no. (%) | 1,162 (53.7) | 972 (44.9) | 8.9e-09 |
| PSL use, no. (%) | 659 (30.5) | 569 (26.3) | 0.003 |
| PSL dose, mg/day | 1.17 ± 2.3 (0–18) | 0.9 ± 2.0 (0–15) | 0.0001 |
| DMARD use, no. (%) | 1,926 (89.0) | 1,921 (88.8) | 0.85 |
| MTX use, no. (%) | 1,671 (77.2) | 1,656 (76.5) | 0.61 |
| MTX dose, mg/week | 6.18 ± 4.8 (0–17.5) | 5.88 ± 4.7 (0–20) | 0.059 |
| Biologic DMARD use, no. (%) | 495 (22.9) | 458 (21.2) | 0.19 |
* Values are mean ± standard deviation (range), unless indicated otherwise.
DAS28 = Disease Activity Score in 28 joints; TJC28 = tender joint count in 28 joints; SJC28 = swollen joint count in 28 joints; TJC45 = tender joint count in 45 joints; SJC45 = swollen joint count in 45 joints; PVAS = patient's assessment of pain on a visual analogue scale; GVAS = patient's global assessment of disease activity on a visual analogue scale; DVAS = physician's global assessment of disease activity on a visual analogue scale; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; WBC = white blood cell count; RF = rheumatoid factor; anti-CCP = anticyclic citrullinated peptide antibodies; J-HAQ = the Japanese version of the Stanford Health Assessment Questionnaire; EQ-5D = the EuroQol 5-dimensional descriptive system; NSAID = nonsteroidal anti-inflammatory drug; PSL = prednisolone; DMARD = disease-modifying antirheumatic drug; MTX = methotrexate.
† Missing data for having current foot or ankle symptoms in the FOOT group (n = 19).
‡ Missing data for having current foot or ankle symptoms in the non-FOOT group (n = 20).