Table 1

Demographic and clinical characteristics at baseline

All patients (n=292)Biological naive (n=203)Switchers (n=89)Switchers with anti-drug antibodies (n=47)Switchers without anti-drug antibodies (n=42)
Demographics
 Age52.8 ± 12.752.6 ± 12.553.4 ± 13.452.5 ± 14.254.4 ± 12.4
 Female, n (%)239 (82)161 (79)78 (88)41 (87)37 (88)
DMARD treatment
 Prior DMARDs2.9 ± 1.32.8 ± 1.23.3 ± 1.4*3.3 ± 1.43.14 ± 1.4
 MTX use, n (%)223 (76)162 (80)61 (69)*29 (62)32 (76)
 MTX dose, mg/week19.7 ± 7.020.6 ± 6.717.3 ± 7.5*15.7 ± 7.418.8 ± 7.4
 Prednisolone use, n (%)84 (29)57 (28)27 (30)17 (36)10 (24)
 Prednisolone dose, mg/day8.2 ± 3.87.7 ± 3.69.2 ± 4.49.6 ± 5.18.5 ± 2.9
 Other DMARD than MTX, n (%)96 (33)81 (40)15 (17)*9 (19)6 (14)
Disease status
 Disease duration, years8 (3–16)6 (2–15)12 (8–17)*14 (9–18)10 (5–17)
 Rheumatoid factor positive, n (%)207 (72)140 (70)67 (75)38 (81)29 (69)
 Erosive disease, n (%)207 (72)135 (67)72 (81)*42 (89)30 (71)
 DAS285.2 ± 1.35.2 ± 1.35.3 ± 1.35.5 ± 1.25.0 ± 1.4
 Erythrocyte sedimentation rate, mm/h23 (12–40)21 (10–38)27 (16–45)*28 (15–46)27 (15–42)
 C reactive protein, mg/litre8 (3–21)7 (3–21)10 (3–21)14 (4–27)8 (3–13)
  • Mean values ± SD, median and IQR, or percentages are shown.

  • * There were significant differences between patients who were anti-TNF naive and switchers for prior DMARDs (p=0.003), MTX use (p=0.028), MTX dose (p=0.001), other DMARDs than MTX (p<0.001), disease duration (p<0.001), erosive disease (p=0.011) and erythrocyte sedimentation rate (p=0.027).

  • There was a significant difference between switchers with and without antibodies for MTX use (p=0.031).

  • DAS28, Disease Activity Score in 28 joints; DMARDs, disease-modifying antirheumatic drugs; MTX, methotrexate.