Table 1

Sensitivity, specificity and likelihood ratio (LR) values for each observer

ObserverSensitivity (95% CI)Specificity (95% CI)Positive LR (95% CI)Negative LR (95% CI)
A First assessment55.8 (47.7 to 63.2)57.9 (39.5 to 74.7)1.32 (0.79 to 2.49)0.76 (0.49 to 1.33)
Second assessment55.8 (47.6 to 61.8)73.7 (55.0 to 87.3)2.12 (1.06 to 4.87)0.60 (0.44 to 0.95)
B First assessment53.4 (45.4 to 58.8)78.9 (60.5 to 91.0)2.53 (1.15 to 6.51)0.59 (0.45 to 0.90)
Second assessment46.5 (38.6 to 50.9)84.2 (66.4 to 94.2)2.94 (1.15 to 8.82)0.64 (0.52 to 0.93)
C First assessment27.9 (20.5 to 32.3)84.2 (67.5 to 94.2)1.77 (0.63 to 5.56)0.86 (0.72 to 1.18)
Second assessment27.9 (20.4 to 33.2)78.9 (61.9 to 90.9)1.32 (0.54 to 3.66)0.91 (0.74 to 1.29)
D First assessment44.2 (36.8 to 52.3)42.1 (25.3 to 60.5)0.76 (0.49 to 1.33)1.33 (0.79 to 2.49)
Second assessment48.8 (40.7 to 56.3)57.9 (39.6 to 74.8)1.16 (0.67 to 2.23)0.88 (0.59 to 1.50)
  • Positive LR, the probability of a positive test result in patients with disease compared with those who do not have the disease.

  • Negative LR, the probability of a negative test result in patients with disease compared with those who do not have the disease.