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Table 4 Diagnostic performance of urine and saliva for detecting Plasmodium antigens with reference to blood

From: Evaluating the potential of using urine and saliva specimens for malaria diagnosis in suspected patients in Ghana

Diagnostic indices Urine specimens Saliva specimens
Overall indices of urine and saliva samples with blood contamination
 True positive 134 217
 True negative 325 325
 False positive 0 0
 False negative 247 164
 Sensitivity (95% CI) 35.2% (30.38–40.20) 57.0% (51.81–61.99)
 Specificity (95% CI) 100% (98.87–100) 100% (98.87–100)
 Accuracy (95% CI) 65.0% (61.37–68.53%) 76.8% (73.51–79.87%)
 PPV (95% CI) 100.0 100.0
 NPV (95% CI) 56.8% (55.00–58.62) 66.46% (63.84–68.99)
 χ2 goodness of fit (p-value) 347.8 (< 0.05) 153.3 (< 0.05)
Diagnostic indices of urine and saliva samples without blood contamination
 True positive 22 28
 True negative 325 325
 False positive 0 0
 False negative 269 182
 Sensitivity (95% CI) 7.6% (4.8–11.2%) 13.3% (9.1–18.7%)
 Specificity (95% CI) 100% (98.9–100) 100% (98.9–100)
 Accuracy (95% CI) 50.2% (46.2–54.2) 53.3% (49.0–57.6)
 PPV (95% CI) 100% 100%
 NPV (95% CI) 48.1% (47.2–48.9) 49.7% (48.3–51.0)
  1. PPV positive predictive value, NPV negative predictive value, 95% CI 95% confidence interval