Table 4.

Baseline disease characteristics of patients (≤ 10 years’ disease duration) with full concordance between the criteria sets and patients with discordance. Results are n (%) or median with interquartile ranges (Q1:Q3).

CharacteristicAll patients, n = 75Concordance**, n = 46Discordance**, n = 29p*
HLA-B2754 (72.0)35 (81.4)19 (73.1)0.548
Sex (men)44 (58.7)29 (63.0)15 (51.7)0.348
Radiographic sacroiliitis52 (69.3)37 (80.4)15 (53.6)0.019
Sacroiliitis MRI28 (37.3)17 (51.5)11 (44.0)0.606
IBP ASAS definition46 (61.3)37 (80.4)9 (31.0)< 0.001
Synovitis33 (44.0)23 (50.0)10 (34.5)0.235
Psoriasis22 (29.3)12 (26.1)10 (34.5)0.449
Raised CRP47 (62.7)31 (73.3)16 (27.3)0.211
Uveitis10 (13.3)5 (10.9)5 (17.2)0.496
Hip involvement6 (8.0)4 (8.7)2 (6.9)1.000
IBD8 (10.7)5 (10.9)3 (10.3)1.000
Family history27 (36.0)17 (37.8)10 (35.7)1.000
Anti-TNF exposure35 (46.1)24 (52.2)11 (37.9)0.246
Response NSAID60 (80.0)53 (84.1)7 (63.6)0.203
Enthesitis (heel)40 (53.3)22 (47.8)18 (62.1)0.246
Dactylitis15 (20.0)10 (21.7)5 (17.2)0.770
Disease Duration, yrs6 (4, 8)7 (3, 8)6 (4, 8)0.734
Age, yrs35 (28, 46)31 (27, 39)48 (35, 56)< 0.001
Age at first symptom, yrs28 (22, 42)24 (21, 31)42 (28, 52)< 0.001
BASDAI, mm25 (12, 45)23 (13, 41)31 (11, 50)0.475
BASFI, mm14 (3, 39)23 (6, 42)13 (4, 32)0.417
  • 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.