Table 5.

European Spondylarthropathy Study Group classification criteria and results of their validation in children

Inflammatory back pain or synovitis –symmetric or predominantly in the lower limbs plus
one of the following
·	Positive family history
·	Psoriasis
·	Inflammatory bowel disease
·	Urethritis, cervicitis, or acute diarrhea within one month before arthritis
·	Buttock pain alternating between right and left gluteal areas
·	Enthesopathy
·	Sacroiliitis

Validated in 361 adults with SpA and 455 controls, such criteria showed a sensitivity of 86.7% and specificity of 87.0% ref. [38].

Validated in 2,982 rheumatic children ref. [74], the diagnostic properties of those criteria were 78.7% for sensitivity, 92.2% for specificity, 58.8% and 96.8% for positive and negative predictive values, respectively, 85.3% for positive likelihood ratio, and 90.3 for diagnostic accuracy. Sensitivity of the criterion “inflammatory back pain” was only 9.1% in children.