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Table 4 Test properties of radiograph for detection of structural lesions consistent with sacroiliitis on MRI

From: Radiographs in screening for sacroiliitis in children: what is the value?

  Rater 1 Rater 2 Rater 3 Rater 4 Rater 5
Percent (95% CI)
 Sensitivity 25.0 (7.3–52.4) 33.3 (7.5–70.1) 75.0 (42.8–94.5) 53.8 (25.1–80.8) 68.4 (43.4–87.4)
 Specificity 90.9 (78.3–97.5) 90.2 (78.6–96.7) 62.5 (47.4–76.0) 78.7 (64.3–89.3) 70.7 (54.5–83.9)
 PPV 50.0 (15.7–84.3) 37.5 (8.5–75.5) 33.3 (16.5–54.0) 41.2 (18.4–67.1) 52.0 (31.3–72.2)
 NPV 76.9 (63.2–87.5) 88.5 (76.6–95.6) 90.9 (75.7–98.1) 86.0 (72.1–94.7) 82.9 (66.4–93.4)
Frequency (%)
 Radiograph–a
  Radiograph–/MRI– 40 (76.9) 46 (88.5) 30 (90.9) 37 (86) 29 (82.9)
  Radiograph–/MRI+ 12 (23.1) 6 (11.5) 3 (9.1) 6 (14) 6 (17.1)
 Radiograph+a
  Radiograph+/MRI– 4 (50) 5 (62.5) 18 (66.7) 10 (58.8) 12 (48)
  Radiograph+/MRI+ 4 (50) 3 (37.5) 9 (33.3) 7 (41.2) 13 (52)
  1. Kappa value interpretations: ≤ 0.40 poor agreement, 0.41–0.59 fair agreement, 0.60–0.74 good agreement, and ≥ 0.75 excellent agreement [21]. For sensitivity, specificity, PPV, and NPV calculations, positive radiograph defined as global impression of sacroiliitis (yes) and reference standard was MRI global impression of structural lesions consistent with sacroiliitis (yes)
  2. CI confidence interval, MRI magnetic resonance imaging, NPV negative predictive value, PPV positive predictive value
  3. aMRI and radiograph + or – defined as global impression of sacroiliitis (yes/no)