Characteristics of TCZ administration group at the initiation of TCZ and at the start of dose frequency adjustment. Values are median (interquartile range) unless otherwise indicated.
| Characteristics | 4-week Interval, n = 246 | 3-week Interval, n = 24 | 5-week Interval, n = 61 | 4-week vs 3-week, p | 4-week vs 5-week, p | 3-week vs 5-week, p |
|---|---|---|---|---|---|---|
| At the TCZ initiation | ||||||
| Age, yrs | 62 (50–69) | 61 (44–67) | 59 (50–67) | 0.57 | 0.19 | 0.77 |
| Female, n (%) | 217/246 (88) | 18/24 (74) | 52/61 (85) | 0.10 | 0.53 | 0.26 |
| Disease duration, mos | 73 (29–168) | 35 (12–107) | 52 (25–137) | 0.03 | 0.28 | 0.20 |
| RF-positive, n (%) | 217/246 (88) | 22/24 (92) | 52/61 (85) | 0.83 | 0.73 | 0.42 |
| Anti-CCP–positive, n (%) | 184/212 (87) | 16/20 (80) | 45/52 (87) | 0.42 | 0.96 | 0.49 |
| MTX use, n (%) | 138/246 (56) | 12/24 (50) | 34/61 (56) | 0.57 | 0.96 | 0.63 |
| MTX dose, mg/week* | 8 (6–10) | 8 (6–10) | 8 (6–10) | 0.87 | 0.18 | 0.51 |
| PSL use, n (%) | 102/246 (41) | 11/24 (46) | 19/61 (31) | 0.67 | 0.14 | 0.20 |
| PSL dose, mg/day* | 5 (4–8) | 6 (4–9) | 5 (3–5) | 0.61 | 0.21 | 0.16 |
| Patients with previous biologic treatment, n (%) | 121/246 (49) | 15/24 (63) | 28/61 (46) | 0.21 | 0.65 | 0.17 |
| No. previous biologic treatment* | 1 (1–2) | 1 (1–2) | 1 (1–2) | 0.47 | 0.58 | 0.85 |
| TJC | 5 (2–9) | 5 (3–12) | 3 (1–8) | 0.24 | 0.06 | 0.03 |
| SJC | 5 (3–9) | 5 (2–10) | 4 (3–7) | 0.47 | 0.02 | 0.55 |
| PtGA | 51 (29–72) | 40 (24–64) | 60 (34–78) | 0.19 | 0.19 | 0.07 |
| PGA | 37 (24–57) | 52 (35–73) | 52 (34–63) | < 0.01 | 0.13 | 0.41 |
| CRP, mg/dl | 1.55 (0.5–3.39) | 3.24 (1.21–5.49) | 1.5 (0.28–2.76) | < 0.01 | 0.26 | < 0.01 |
| ESR, mm/h | 49 (32–77) | 75 (38–108) | 46 (23–74) | 0.03 | 0.37 | 0.02 |
| CDAI | 20.2 (12.0–28.4) | 20.2 (13.4–35.9) | 19.4 (15.3–27.3) | 0.32 | 0.24 | 0.93 |
| DAS28-ESR | 5.13 (4.40–6.27) | 5.69 (4.60–6.90) | 4.98 (3.96–6.33) | 0.08 | 0.53 | 0.06 |
| HAQ-DI | 1 (0.5–1.75) | 1.125 (0.375–2.0) | 1.125 (0.75–1.63) | 0.90 | 0.44 | 0.96 |
| At the dose frequency adjustment | ||||||
| TJC | — | 3 (1–10) | 0 (0–1) | — | — | < 0.01 |
| SJC | — | 4 (1–9) | 0 (0–0) | — | — | < 0.01 |
| PtGA | — | 27 (13–64) | 5 (2–11) | — | — | < 0.01 |
| PGA | — | 61 (23–80) | 0 (0–5) | — | — | < 0.01 |
| CRP, mg/dl | — | 0.33 (0.01–3.20) | 0.01 (0.01–0.02) | — | — | < 0.01 |
| ESR, mm/h | — | 22 (8–101) | 5 (2–7) | — | — | < 0.01 |
| CDAI | — | 14.5 (7.9–34.0) | 1.1 (0.3–2.4) | — | — | < 0.01 |
| DAS28-ESR | — | 4.2 (2.8–6.5) | 1.3 (0.8–1.8) | — | — | < 0.01 |
| HAQ-DI | — | 1.625 (0.5–2.25) | 0.125 (0–0.5) | — | — | < 0.01 |
↵* Median (interquartile range) of PSL/MTX dose; no. previous biologic treatments are calculated from patients who had PSL/MTX or previous biologic treatment. TCZ: tocilizumab; RF: rheumatoid factor; anti-CCP: anticyclic citrullinated peptide antibodies; MTX: methotrexate; PSL: prednisolone; TJC: tender joint count; SJC: swollen joint count; PtGA: patient’s global assessment; PGA: physician’s global assessment; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; CDAI: Clinical Disease Activity Index; DAS28-ESR: 28-joint Disease Activity Score based on ESR; HAQ-DI: Health Assessment Questionnaire–Disability Index.