Table 2 Baseline characteristics of the British Society for Rheumatology Biologics Register (BSRBR) patients with rheumatoid arthritis (RA), by treatment group
Control (DMARD) (n = 2880)All anti-TNFα (n = 9826)p ValueSpecific anti-TNFα treatment
Etanercept (n = 3910)Infliximab (n = 3206)Adalimumab (n = 2710)p Value
Age, mean (SD)60.0 (12.4)56.2 (12.2)<0.00155.9 (12.2)55.9 (12.4)56.8 (11.9)0.005
Female, %72%76%<0.00177%76%75%0.055
Disease duration (years), median (IQR)7 (1 to 15)11 (6 to 19)<0.00112 (6 to 19)12 (6 to 19)11 (5 to 19)0.002
Smoking, %:
    Current24%22%0.00221%22%24%0.036
    Former40%38%38%38%38%
    Never36%40%41%40%38%
HAQ, median (IQR)1.6 (1.0 to 2.1)2.1 (1.8 to 2.5)<0.0012.1 (1.8 to 2.5)2.1 (1.8 to 2.5)2.0 (1.6 to 2.4)<0.001
DAS28, mean (SD)5.0 (1.3)6.6 (1.0)<0.0016.6 (1.0)6.6 (1.0)6.5 (1.0)<0.001
Calendar year, median (IQR)2004 (2004 to 2005)2003 (2003 to 2004)<0.0012004 (2003 to 2004)2003 (2002 to 2003)2004 (2003 to 2005)<0.001
  • IQR, interquartile range.