Table 1 Demographic data and baseline characteristics
VariablesBaseline3 Months6 Months
Males (number, %)40 (76)
Age (years)41 (11)
Caucasian (number, %)45 (85)
BMI25 (4.4)
HLA B27 + (number, %)44 (88)
Peripheral arthritis (number, %)28 (53)
BASDAI6.4 (1.3)3.1 (2.0)*2.5 (1.7)*
Patient Global Disease Activity score7.2 (1.9)3.2 (2.4)*2.5 (2.1)*
BASFI6.2 (2.1)4.1 (2.5)*3.5 (2.5)*
ESR (median, range)22 (1–114)5 (1–58)*4 (1–33)*
CRP (median, range)17 (1–92)4 (1–44)*4 (1–74)*
Serum etanercept levels02.7 (1.2)3.0 (1.0)
Antibodies to etanercept000
  • Except where indicated otherwise, the values are the mean (SD). Mean serum etanercept and antibodies to etanercept levels are in mg/litre. Normal CRP <8.0 mg/litre; normal ESR <10 mm/h.

  • *Significance level: p<0.001.

  • BASDAI, Bath Ankylosing Spondylitis Disease Activity Index (0–10); BASFI, Bath Ankylosing Spondylitis Functional Index (0–10); BMI, body mass index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HLA B27, human leukocyte antigen B27.