Table 1

Patient characteristics at initiation of first TNF inhibitor between 2003 and 2011 in 9139 Swedish patients with rheumatoid arthritis*

Etanercept (n=3892)Adalimumab (n=2349)Infliximab (n=2898)p Value†
Sex, n (%)
 Women2995 (77%)1766 (75%)2151 (74%)0.03
Age (years)
 Mean (SD)55.1 (13.7)55.7 (13.3)56.7 (13.1)<0.001
Rheumatoid factor status, n (%)
 Positive496 (74%)267 (76%)389 (75%)<0.001
 Negative2082 (18%)1301 (16%)1563 (18%)
Unspecified281 (8.3%)146 (8.0%)132 (7.2%)
HAQ, n (%)
 Mean (SD)1.15 (0.64)1.15 (0.65)1.20 (0.64)0.002
 <1.001334 (34%)811 (35%)895 (31%)<0.001
 1.00–1.491048 (27%)623 (27%)727 (25%)
 1.5–1.99656 (17%)419 (18%)536 (18%)
 ≥2.00452 (12%)273 (12%)360 (12%)
Missing402 (10%)223 (9.5%)380 (13%)
DAS28, n (%)
 Mean (SD)5.1 (1.4)5.1 (1.4)5.2 (1.4)0.004
 <3.2318 (8.2%)176 (7.5%)207 (7.1%)<0.01
 3.2–5.11371 (35%)832 (35%)935 (32%)
 ≥5.21617 (42%)1019 (43%)1276 (44%)
Missing586 (15%)322 (14%)480 (17%)
Disease duration (years), n (%)
 Mean (SD)12 (14)13 (16)13 (17)<0.01
 Median (p25–75)7 (3–16)8 (3–17)8 (3–16)
 <1 year259 (6.7%)143 (6.1%)251 (8.7%)0.002
 1–4.9 year1218 (31%)681 (29%)870 (30%)
 5–9.9 year794 (20%)468 (20%)559 (19%)
 ≥101579 (41%)1022 (44%)1187 (41%)
Missing113 (1.1%)35 (1.5%)31 (1.1%)
TNF inhibitors, n (%)
 2003–20051240 (39%)852 (27%)1076 (34%)<0.001
 2006–20091915 (46%)1041 (25%)1228 (29%)
 2010–2011737 (41%)456 (26%)594 (33%)
Concomitant DMARDs, n (%)
 No1072 (28%)561 (24%)335 (12%)<0.001
 MTX2267 (58%)1443 (61%)2162 (75%)
 Other553 (14%)345 (15%)401 (14%)
Hospital days‡
 Mean (SD)4 (13)4 (11)5 (14)0.002
 Median (p25–75)0 (0–3)0 (0–3)0 (0–4)
Outpatient visits‡
 Mean (SD)11 (9)9 (8)10 (8)<0.001
 Median (p25–75)9 (5–15)7 (4–13)8 (4–13)
  • *p25–75=25th to 75th centile.

  • †Calculated using ANOVA with Bonferroni correction.

  • ‡Assessed during the 2 years preceding TNFi treatment initiation. Data on hospital days and non-primary outpatient care visits retrieved from the Swedish National Patient Register between 2001 and 2009, and include admissions and visits due to any cause.

  • ACR, American College of Rheumatology; ANOVA, analysis of variance; DAS28, disease activity score 28 joint count; DMARD, disease modifying antirheumatic drug; HAQ, health assessment questionnaire; MTX, methotrexate; TNF, tumour necrosis factor; TNFi, TNF inhibitor.