Table 4

Comparison of the combined criteria for axial SpA and for peripheral SpA (set 2D), ESSG criteria and Amor criteria in the entire ASAS study population (n=975)

Sets of criteria for SpASensitivity (%)Specificity (%)
Modified ESSG (with MRI)*79.168.8
Modified Amor (with MRI)67.586.7
Combination of ASAS criteria for axial SpA (in patients with predominant back pain with or without peripheral manifestations) and criteria for peripheral SpA set 2D (arthritis/enthesitis/dactylitis plus (A) ≥1 of psoriasis, inflammatory bowel disease, preceding infection, HLA-B27, uveitis, sacroiliitis on imaging, or (B) ≥2 other parameters**) for patients with peripheral manifestations only79.583.3
  • * The ESSG criteria were modified in that active sacroiliitis on MRI was added to the list of parameters of which at least one is required in addition to inflammatory back pain or synovitis.

  • The Amor criteria were modified in that active sacroiliitis on MRI was assigned 3 scoring points, similar to definite radiographic sacroiliitis. Thus, presence of either definite radiographic sacroiliitis or active sacroiliitis on MRI yielded 3 points (maximum of 3 points for the imaging criterion).

  • Sacroiliitis on imaging refers to definite radiographic sacroiliitis according to the mod. New York criteria or sacroiliitis on MRI according to the consensus definition.9 ASAS, Assessment of SpondyloArthritis international Society; ESSG, European Spondylarthropathy Study Group; HLA-B27, human leucocyte antigen B27; SpA, spondyloarthritis.