Table 2.

Baseline disease characteristics with comparison of patients with full concordance with criteria sets and patients with discordance. Results are n (%) or median with interquartile ranges (Q1:Q3).

CharacteristicAll Patients, n = 231Concordance**, n = 169Discordance**, n = 62p*
HLA-B27176 (76.2)137 (86.2)39 (70.9)0.014
Sex (men)145 (62.8)107 (63.3)38 (61.3)0.878
Radiographic sacroiliitis190 (82.3)147 (88.6)43 (71.7)0.004
Sacroiliitis MRI66 (28.6)46 (49.5)20 (46.5)0.854
IBP ASAS definition154 (66.7)139 (82.2)15 (24.2)< 0.001
Synovitis103 (44.6)88 (52.4)15 (24.2)< 0.001
Psoriasis64 (27.7)46 (27.4)18 (29.0)0.869
Raised CRP150 (64.9)114 (75.0)36 (64.3)0.163
Uveitis69 (29.9)55 (32.7)14 (22.6)0.148
Hip involvement44 (19.0)36 (21.0)8 (12.9)0.187
IBD21 (9.1)17 (10.1)4 (6.5)0.606
Family history97 (42.0)76 (45.5)21 (35)0.173
Anti-TNF to exposure143 (61.9)114 (67.5)29 (46.8)0.006
Response to NSAID192 (83.1)144 (85.7)48 (80.0)0.307
Enthesitis (heel)117 (50.6)88 (52.1)29 (46.8)0.553
Dactylitis47 (20.3)38 (22.5)9 (14.5)0.202
Disease duration, yrs16 (8, 27)18 (10, 27)11 (6, 20)0.002
Age, yrs44 (35, 55)42 (39, 50)51 (39, 59)0.001
Age at first symptom, yrs24 (18, 32)22 (17, 27)33 (23, 49)< 0.001
BASDAI, mm28 (15, 44)27 (14, 43)31 (15, 45)0.549
BASFI, mm23 (6, 42)22 (5, 39)26 (7, 52)0.148
  • On the number of available data.

  • * Comparing the concordant with the discordant group.

  • ** Concordance defined as a patient fulfilling the 3 criteria, discordance defined as a patient that did not fulfill all 3 criteria. MRI: magnetic resonance imaging; ASAS: Assessment in Spondyloarthritis International Society; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; BASFI: Bath Ankylosing Spondylitis Functional Index; CRP: C-reactive protein; IBD: inflammatory bowel disease; IBP: inflammatory back pain; NSAID: nonsteroidal antiinflammatory drugs; TNF: tumor necrosis factor.