Number of SpA features | X-SI status | HLA-B27/MRI status | Rheumatologist SpA diagnosis yes | Rheumatologist SpA diagnosis no | ASAS axSpA classification yes | ASAS axSpA classification no |
---|---|---|---|---|---|---|
0–1 n=159 | X-SI+ n=9 | HLA-B27+/MRI+ | 4 | 4 | ||
HLA-B27+/MRI− | 1 | 1 | 2 | |||
HLA-B27−/MRI+ | 1 | 1 | ||||
HLA-B27−/MRI− | 2 | 2 | ||||
X-SI− n=150 | HLA-B27+/MRI+ | 6 | 1 | 7 | ||
HLA-B27+/MRI− | 7 | 16 | 23 | |||
HLA-B27−/MRI+ | 15 | 6 | 14 | 7 | ||
HLA-B27−/MRI− | 2 | 97 | 99 | |||
Mean level of confidence regarding diagnosis (SD) | 6.9 (2.3) | 7.5 (2.4) | ||||
2 n=143 | X-SI+ n=16 | HLA-B27+/MRI+ | 14 | 14 | ||
HLA-B27+/MRI− | 1 | 1 | ||||
HLA-B27−/MRI+ | 1 | 1 | ||||
HLA-B27−/MRI− | ||||||
X-SI− n=127 | HLA-B27+/MRI+ | 15 | 15 | |||
HLA-B27+/MRI− | 15 | 20 | 35 | |||
HLA-B27−/MRI+ | 5 | 2 | 7 | |||
HLA-B27−/MRI− | 11 | 59 | 70 | |||
Mean level of confidence regarding diagnosis (SD) | 7.6 (1.9) | 6.7 (2.3) | ||||
3 n=79 | X-SI+ n=5 | HLA-B27+/MRI+ | 3 | 3 | ||
HLA-B27+/MRI− | 1 | 1 | ||||
HLA-B27−/MRI+ | 1 | 1 | ||||
HLA-B27−/MRI− | ||||||
X-SI− n=74 | HLA-B27+/MRI+ | 17 | 17 | |||
HLA-B27+/MRI− | 11 | 9 | 20 | |||
HLA-B27−/MRI+ | 8 | 8 | ||||
HLA-B27−/MRI− | 8 | 21 | 29 | |||
Mean level of confidence regarding diagnosis (SD) | 8.0 (1.9) | 7.1 (2.0) | ||||
≥4 n=119 | X-SI+ n=28 | HLA-B27+/MRI+ | 15 | 15 | ||
HLA-B27+/MRI− | ||||||
HLA-B27−/MRI+ | 8 | 8 | ||||
HLA-B27−/MRI− | 5 | 5 | ||||
X-SI− n=91 | HLA-B27+/MRI+ | 16 | 16 | |||
HLA-B27+/MRI− | 21 | 4 | 25 | |||
HLA-B27−/MRI+ | 8 | 8 | ||||
HLA-B27−/MRI− | 28 | 14 | 42 | |||
Mean level of confidence regarding diagnosis (SD) | 8.0 (2.0) | 7.3 (1.7) |
Diagnosis based on information after full diagnostic workup: medical history, physical examination, imaging and laboratory testing. ASAS axSpA criteria, ASAS criteria for axial spondyloarthritis. Mean level of confidence regarding diagnosis: 0 (not confident at all) through 10 (very confident).
AxSpA, axial spondyloarthritis; ASAS, Assessment of SpondyloArthritis international Society; HLA-B27, human leucocyte antigen B27; X-SI, radiograph of sacroiliac joints; SpA, spondyloarthritis.