Table 1

Patient characteristics at baseline

 Patients with complete sets of radiographsAll patients
Continuous (n=62)On demand (n=60)Continuous (n=85)On demand (n=82)
Age, mean (SD)40.7 (9.6)45 (10.4)*41.7 (10.4)43.8 (10.8)
Males, n (%)44 (71.0)40 (66.7)63 (74.1)56 (68.3)
Disease duration in years, mean (SD)12.8 (11.3)17.0 (12.6)*12.2 (10.3)15.2 (12.4)
HLA-B27 positive, n (%)55 (88.7)55 (91.7)71 (83.5)68 (84)
BASDAI, mean (SD)4.1 (1.5)4.2 (1.5)4.2 (1.6)4.5 (1.6)
BASFI, mean (SD)2.9 (2.1)3.7 (2.2)*3.1 (2.2)3.9 (2.2)*
ASDAS (CRP), mean (SD)2.7 (0.7)2.8 (0.7)2.7 (0.8)2.9 (0.8)
CRP, mg/L, mean (SD)7.8 (7.4)12.5 (15.1)8.4 (8.1)12.9 (15.5)
CRP>5 mg/L, n (%)33 (54.1)35 (58.3)46 (55.4)47 (57.3)
BASMI, mean (SD)2.1 (2.1)3 (2.3)2.2 (2.1)2.7 (2.2)
mSASSS, mean (SD)10.9 (15.5)16.4 (18.2)11.3 (14.9)14.0 (16.8)
Patients with syndesmophytes at baseline, n (%)33 (53.2)37 (61.7)47 (55.3)47 (57.3)
Current smoker, n (%)36 (59)20 (33.3)*44 (52.4)33 (40.2)
Previous smoker n (%)14 (22.6)20 (33.3)19 (22.4)23 (28.0)
  • Values are means (SDs) if not otherwise specified.

  • *Significant differences (p<0.05) between treatment groups.

  • ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; CRP, C reactive protein; HLA, human leucocyte antigen; mSASSS, modified Stoke Ankylosing Spondylitis Spine Score.