Table 2 Sensitivity and specificity of new classification criteria for axial SpA (set 1 and set 2) in comparison with ESSG and Amor criteria in paper patients*

Criteria for SpA	Sensitivity (%)	Specificity (%)
Candidate criteria for axial SpA (set 1)	97.1	94.7
Candidate criteria for axial SpA (set 2)	86.1	94.7
ESSG	33.3	89.5
Modified ESSG (with MRI)†	47.2	89.5
Amor	61.1	100
Modified Amor (with MRI)‡	94.4	94.4

*n = 55 classifiable patients; n = 36 axial spondyloarthritis (SpA); n = 19 no SpA. †The European Spondylarthropathy Study Group (ESSG) criteria were modified in that active sacroiliitis on magnetic resonance imaging (MRI) was added to the list of parameters 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.