Table 3

 Test performance of modifications of the Berlin algorithm in the early spondyloarthritis clinic cohort with “fulfilment of Amor and European Spondylarthropathy Study Group criteria for spondyloarthritis” as gold standard

Order of application
HLA-B27 firstMRI first
AS, ankylosing spondylitis; HLA-B27, human leucocyte antigen B27; LR, likelihood ratio; MRI, magnetic resonance imaging; NPV, negative predictive value; PPV, positive predictive value.
LR-positive test, sensitivity/(1−specificity).
LR-negative test, (1−sensitivity)/specificity.
All patients (n = 68)
    Sensitivity77%84%
    Specificity56%72%
    NPV74%72%
    PPV69%84%
    LR-positive test1.83.0
    LR-negative test0.410.22
Only patients who are not fulfilling the modified New York criteria for AS (n = 54)
    Sensitivity68%76%
    Specificity70%72%
    NPV56%72%
    PPV79%76%
    LR-positive test2.32.7
    LR-negative test0.460.33