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Table 4 Statistical indicators of PCR diagnosis performance

From: Plasmodium malariae in the Colombian Amazon region: you don’t diagnose what you don’t suspect

Estimator/aspect

Sensitivity (%) [95% CI]b

Specificity (%) [95% CI]b

(PPV) (%) [95% CI]a,b

(NPV) (%) [95% CI]a,b

Accuracy (%) [95% CI]b

Youden index [95% CI]b

(AUC) [95% CI]

Plasmodium spp.

99.81 [99.00, 100.49]

23.79 [20.83, 26.74]

50.60 [47.51, 53.68]

99.39 [96.75, 101.65]

57.15 [54.34, 59.99]

0.24 [0.20, 0.27]

0.611 [0.596, 0.626]

Pf

55.82 [46.27, 65.41]

85.24 [83.21, 87.14]

26.44 [20.61, 32.48]

95.31 [93.98, 96.63]

82.69 [80.60, 84.75]

0.41 [0.31, 0.51]

0.702 [0.653, 0.751]

Pv

90.18 [87.55, 92.67]

44.13 [40.31, 48.06]

57.60 [53.84, 61.49]

84.23 [80.05, 88.24]

65.18 [62.12, 68.25]

0.34 [0.29, 0.39]

0.647 [0.626, 0.667]

Pf/Pv

8.34 [−0.17, 27.93]

92.03 [90.57, 93.45]

1.51 [−0.02, 5.04]

98.56 [97.64, 99.35]

90.82 [89.21, 92.41]

0.00 [−0.09, 0.20]

0.502 [0.42, 0.584]

  1. Sensitivity, specificity, predictive values and performance index values for PCR assay regarding: the detection of the disease in general (any Plasmodium spp.), the detection of P. falciparum or P. vivax (bearing in mind samples classified as co-infection) and the detection of P. falciparum/P. vivax mixed infections
  2. PPV, positive predictive value; NPV, negative predictive value; AUC, area under the ROC curve; CI, confidence interval; Pf, Plasmodium falciparum; Pv, Plasmodium vivax; co-infections are separated by a slash (/) sign
  3. aValue adjusted for prevalence
  4. bValue adjusted for imperfect gold standard