Table 1

Baseline characteristics

Women (n=326)Men (n=957)p Value*
Ethnicity, n (%)0.110
 White306 (93.9)871 (91.0)
 Asian3 (0.9)34 (3.6)
 Black2 (0.6)2 (0.2)
 Latin American9 (2.8)29 (3.0)
 Other6 (1.8)21 (2.2)
Age of diagnosis (years), mean (SD)35.0 (11.2)31.2 (10.6)<0.001
Disease duration (years), mean (SD)7.4 (7.4)9.5 (9.1)<0.001
HLA-B27 positive, n (%)244 (76.3)795 (85.2)<0.001
C-reactive protein (mg/l), mean (SD)13.1 (16.0)20.9 (23.4)<0.001
ASDAS score, mean (SD)3.6 (0.8)3.7 (0.8)0.065
BASDAI score, mean (SD)62.7 (16.2)58.6 (16.4)<0.001
BASFI score, mean (SD)57.5 (20.5)55.8 (20.3)0.194
Nocturnal back pain score, mean (SD)65.2 (21.7)61.4 (22.3)0.008
Patient global assessment, mean (SD)66.2 (19.9)62.4 (20.5)0.004
Total back pain score, mean (SD)66.1 (20.3)61.4 (20.0)<0.001
  • *Between-group p value, from a one-way analysis of variance with treatment as a factor for continuous variables and a Cochran–Mantel–Haenszel test for categorical variables.

  • ASDAS, ankylosing spondylitis disease activity score; BASDAI, Bath AS disease activity index; BASFI, Bath AS functional index.