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Table 2 Empirical estimates of sensitivity (SS), specificity (SP), negative predictive value (NPV) and positive predictive value (PPV), Cohen’s kappa for each diagnostic test against Malaria by RDT as ‘gold standard’

From: Non-invasive surveillance of Plasmodium infection by real-time PCR analysis of ethanol preserved faeces from Ugandan school children with intestinal schistosomiasis

Assay Negative (%) Positive (%) Total (%) Estimate % (95% CIs) Diagnostic accuracy (95% CIs) Diagnostic odds (95% CIs) Cohen’s kappa
Rapid diagnostic tests (RDTs)
 rtPCR of DBSa
  Negative 41 (83.6) 8 (16.3) 49 (19.8) Sensitivity 94.2% [88.9–97.0] 69.2% [63.2–74.6] 9.7 [4.3–22.0] 0.3 [0.2–0.4]
  Positive 68 (34.3) 130 (65.6) 198 (80.1) Specificity 37.6% [29.0–46.9]
  Total (%) 109 (44.1) 138 (55.8) 247 (100.0) PPV 65.6% [58.8–71.9]
     NPV 83.6% [70.9–91.4]
 rtPCR of EPFa
  Negative 52 (58.4) 37 (41.5) 89 (36.0) Sensitivity 73.1% [65.2–79.8] 61.9% [55.7–67.7] 2.4 [1.4–4.2] 0.2 [0.1–0.3]
  Positive 57 (36.0) 101 (63.9) 158 (63.9) Specificity 47.7% [38.5–57.0]
  Total (%) 109 (44.1) 138 (55.8) 247 (100.0) PPV 63.9% [56.1–71.0]
     NPV 58.4% [48.0–68.1]
  1. artPCR-based assays based on detecting a region of the Plasmodium 18S DNA gene that is conserved across all five species P. falciparum, P. vivax, P. ovale and P. malariae