Table 4

Concordance between clinical axSpA diagnosis and presence of HLA-B27 for all patients and stratified for total number of SpA features

 Clinical axSpA diagnosis
YesNoTotal
All patients
HLA-B27 positive
 Yes14751198
 No103199302
 Total250250500
 OR (95% CI)5.6 (3.7 to 8.3)
1 feature 
HLA-B27 positive
 Yes181836
 No20103123
 Total38121159
 OR (95% CI)5.2 (2.3 to 11.6)
2 features
HLA-B27 positive
 Yes452045
 No176178
 Total6281143
 OR (95% CI)8.1 (3.8 to 17.1)
3 features
HLA-B27 positive
 Yes32941
 No172138
 Total493079
 OR (95% CI)4.4 (1.7 to 11.7)
4 features
HLA-B27 positive
 Yes52456
 No491463
 Total10118119
 OR (95% CI)3.7 (1.1 to 12.1)
  • axSpA, axial spondyloarthritis; HLA-B27, human leucocyte antigen B27; SpA, spondyloarthritis.