Sensitivity and specificity of candidate criteria: nr-axSpA versus NSBP
| Cohort | A | B | ||||||
|---|---|---|---|---|---|---|---|---|
| Sens | Spec (NSBP+HC) | LR+ | LR− | Sens | Spec | LR+ | LR− | |
| Global assessment | 0.74 | 0.95 (0.94) | 14.38 | 0.28 | 0.44 | 0.83 | 2.50 | 0.68 |
| ASAS definition | 0.80 | 0.76 (0.74) | 3.28 | 0.26 | 0.42 | 0.74 | 1.58 | 0.79 |
| MORPHO definition | 0.88 | 0.72 (0.71) | 3.17 | 0.17 | 0.54 | 0.72 | 1.93 | 0.64 |
| ER ≥2 | 0.58 | 0.97 (0.97) | 17.94 | 0.44 | 0.30 | 0.90 | 3.03 | 0.78 |
| BMO ≥2 | 0.80 | 0.76 (0.74) | 3.37 | 0.26 | 0.42 | 0.73 | 1.54 | 0.80 |
| BMO ≥2 and/or ER ≥1 | 0.88 | 0.72 (0.71) | 3.17 | 0.17 | 0.55 | 0.70 | 1.81 | 0.65 |
| BMO ≥2 and/or ER ≥2 | 0.88 | 0.73 (0.72) | 3.25 | 0.17 | 0.53 | 0.71 | 1.85 | 0.66 |
| BMO ≥3 | 0.75 | 0.89 (0.88) | 6.50 | 0.28 | 0.34 | 0.84 | 2.13 | 0.79 |
| BMO ≥3 and/or ER ≥1 | 0.83 | 0.85 (0.84) | 5.36 | 0.21 | 0.48 | 0.79 | 2.24 | 0.67 |
| BMO ≥3 and/or ER ≥2 | 0.83 | 0.85 (0.85) | 5.60 | 0.21 | 0.46 | 0.82 | 2.53 | 0.66 |
| BMO ≥4 | 0.70 | 0.92 (0.92) | 9.10 | 0.32 | 0.27 | 0.87 | 2.13 | 0.83 |
| BMO ≥4 and/or ER ≥1 | 0.78 | 0.88 (0.88) | 6.36 | 0.26 | 0.44 | 0.80 | 2.13 | 0.71 |
| BMO ≥4 and/or ER ≥2 | 0.78 | 0.89 (0.89) | 7.11 | 0.25 | 0.42 | 0.83 | 2.52 | 0.70 |
Sensitivity, specificity and likelihood ratios are expressed as mean values over four readers. The gold standard for calculating sensitivity and specificity was rheumatologist expert opinion.
ASAS, Assessment in SpondyloArthritis international Society definition: ≥2 SIJ quadrants with BMO on the same MRI slice or BMO in the same SIJ quadrant on ≥2 consecutive MRI slices; BMO, bone marrow oedema; ER, erosion; HC, healthy control; LR−, negative likelihood ratio; LR+, positive likelihood ratio; MORPHO definition, ≥2 SIJ quadrants with BMO on the same MRI slice or BMO in the same SIJ quadrant on ≥2 consecutive MRI slices or ≥2 SIJ quadrants with erosion on the same MRI slice or erosion in the same SIJ quadrant on ≥2 consecutive MRI slices or ≥1 SIJ quadrant with BMO plus ≥1 SIJ quadrant with erosion4; MRI, magnetic resonance imaging; nr-axSpA, non-radiographic axial spondyloarthritis; NSBP, non-specific back pain; Sens, sensitivity; SIJ, sacroiliac joint; Spec, specificity.