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Table 2 Diagnostic performance of RDT in the detection of CE and AE

From: Field evaluation of an immunochromatographic test for diagnosis of cystic and alveolar echinococcosis

Diagnostic parameter

CE (95% CI)

AE (95% CI)

True positive (tp)

258

161

True negative (tn)

1031a

1017b

False positive (fp)

31

45

False negative (fn)

16

4

Sensitivityc (%)

94.2 (90.7–96.6)

97.5 (93.9–99.3)

Specificityd (%)

97.1 (95.9–98.0)

95.8 (94.3–96.9)

Positive likelihood ratioe

32.3 (22.8–45.7)

23.0 (17.3–30.7)

Negative likelihood ratiof

0.06 (0.04–0.10)

0.03 (0.01–0.07)

Positive predictive valueg (%)

89.3 (85.5–92.2)

78.2 (72.8–82.7)

Negative predictive valueh (%)

98.5 (97.6–99.0)

99.6 (99.0–99.9)

Accuracyi (%)

96.5 (95.3–97.4)

96.0 (94.8–97.0)

  1. Abbreviation: CI confidence interval
  2. aTrue negative = total no. of negative minus no. of CE positive (1062 minus 31)
  3. bTrue negative = total no. of negative minus no. of AE positive (1062 minus 45)
  4. cSensitivity = \( \frac{\mathrm{tp}}{\mathrm{tp}+\mathrm{fn}} \) × 100
  5. dSpecificity = \( \frac{\mathrm{tn}}{\mathrm{tn}+\mathrm{fp}} \) × 100
  6. ePositive likelihood ratio = \( \frac{\mathrm{sensitivity}}{1-\mathrm{specificity}} \)
  7. fNegative likelihood ratio = \( \frac{1-\mathrm{sensitivity}}{\mathrm{specificity}} \)
  8. gPositive predictive value = \( \frac{\mathrm{tp}}{\mathrm{tp}+\mathrm{fp}} \)
  9. hNegative predictive value = \( \frac{\mathrm{tn}}{\mathrm{tn}+\mathrm{fn}} \)
  10. iAccuracy = \( \frac{\mathrm{tp}+\mathrm{tn}}{\mathrm{tp}+\mathrm{tn}+\mathrm{fp}+\mathrm{fn}} \)