Performance of different tests to support the diagnosis of SpA.
| R, n = 80 | R + HLA-B27, n = 67 | R + HLA-B27 + FC, n = 67 | FC, n = 99 | HLA-B27 + FC, n = 81 | R + FC, n = 80 | |
|---|---|---|---|---|---|---|
| Sensitivity (95% CI) | 36% (24–50) | 67% (52–79) | 74% (59–85), p = 0.2482* | 21% (11–35) | 71% (57–82) | 55% (41–68) p = 0.0026** |
| Specificity (95% CI) | 94% (80–98) | 84% (65–94) | 84% (65–94) | 98% (89–100) | 78% (62–88) | 88% (73–95) |
| LR (95% CI) | 6.0 (1.5–24.1) | 4.2 (1.7–10.5) | 4.6 (1.8–11.5) | 9.9 (1.3–74.1) | 3.2 (1.7–6.1) | 4.6 (1.8–11.8) |
| OR (95% CI) | 8.8 (1.9–41.3) | 10.5 (3.0–36.5) | 14.8 (4.1–52.8) | 12.3 (1.5–99.8) | 8.6 (3.1–23.8) | 9.0 (2.7–29.6) |
↵* McNemar test (paired proportions) versus R + HLA-B27.
↵** McNemar test (paired proportions) versus R. With n = no. patients for which the test(s) was/were performed. SpA: spondyloarthritis; R: radiology (radiograph and/or MRI); FC: fecal calprotectin analysis with LIAISON Calprotectin performed at cutoff of 62 µg/g, corresponding to a 98% specificity for SpA; LR: likelihood ratio; MRI: magnetic resonance imaging.