Demographic and clinical characteristics at baseline
| Total population (N=235) | Anti-TNF naive patients (n=183) | IFX switchers (n=52) | IFX switchers with anti-IFX (n=33) | IFX switchers without anti-IFX (n=19) | |
|---|---|---|---|---|---|
| Demographics | |||||
| Age, years | 53±12 | 53±12 | 52±12 | 54±10 | 49±13 |
| Female, n (%) | 185 (79) | 142 (78) | 43 (83) | 27 (82) | 16 (84) |
| DMARD treatment | |||||
| Prior DMARDs | 3.5±1.7 | 3.2±1.4*,†,‡ | 4.4±2.2* | 4.3±2.2† | 4.7±2.1‡ |
| Methotrexate use, n (%) | 193 (82) | 150 (82) | 43 (83) | 28 (85) | 15 (79) |
| Methotrexate dose (mg/week) | 23 (15–25) | 25 (15–25) | 20 (13–25) | 18 (11–25) | 20 (15–25) |
| Prednisone use, n (%) | 80 (34) | 56 (31)*,‡ | 24 (46)* | 13 (39) | 11 (58)‡ |
| Prednisone dose (mg/day) | 7.5 (5–10) | 7.0 (5–10)†,‡ | 7.5 (5–10) | 5 (4-6)†,§ | 10 (10–10)‡,§ |
| Disease status | |||||
| Disease duration (years) | 9 (4–17) | 8 (4–17) | 12 (6–18) | 13 (6–18) | 9 (3–17) |
| Rheumatoid factor positive, n (%) | 171 (73) | 130 (71) | 41 (79) | 28 (85) | 13 (68) |
| Erosive disease, n (%) | 182 (77) | 140 (77)*,† | 42 (81)*,† | 28 (85) | 14 (74) |
| Erythrocyte sedimentation rate (mm/h) | 29±23 | 28±22 | 36±26 | 37±27 | 33±23 |
| C-reactive protein (mg/dl) | 11 (5–24) | 11 (5–24) | 10 (3–35) | 8 (2–36) | 14 (5–35) |
| DAS28 | 5.2±1.2 | 5.1±1.2 | 5.4±1.3 | 5.3±1.2 | 5.7±1.4 |
Mean values ± SD, median (IQR) or percentages are shown.
↵* There were significant differences between anti-TNF naive patients and switchers for prior DMARDs (p=0.000), prednisone use (p=0.037) and erythrocyte sedimentation rate (ESR) (p=0.025).
↵† There were significant differences between anti-TNF naive patients and switchers with anti-infliximab for prior DMARDs (p=0.009), prednisone dose (p=0.013) and ESR (p=0.027).
↵‡ Between anti-TNF naive and switchers without anti-IFX for prior DMARDs (p=0.006) and prednisone use (p=0.016) and dose (p=0.007).
↵§ There was a significant difference between infliximab switchers with and without anti-infliximab for prednisone dose (p=0.000).
DAS28, Disease Activity Score in 28 joints; DMARDs, disease modifying antirheumatic drugs; IFX, infliximab; TNF, tumour necrosis factor.