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Table 4 Showing the performance measures of Kato-Katz by each survey round with POC-CCA as the gold standard

From: Comparing the performance of circulating cathodic antigen and Kato-Katz techniques in evaluating Schistosoma mansoni infection in areas with low prevalence in selected counties of Kenya: a cross-sectional study

Treatment round Sensitivity %(95% CI) Specificity %(95% CI) LR+ %(95% CI) LR %(95% CI) PPV %(95% CI) NPV %(95% CI) Kappa index (Agreement %)
Pre-treatment 12.5 (9.7–15.8) 97.9 (97.0–98.6) 6.0 (3.8–9.3) 0.9 (0.9–0.9) 69.0 (58.1–78.5) 75.0 (72.8–77.0) 0.14 (74.7%)
Post-treatment 5.2 (3.2–7.9) 99.5 (99.0–99.8) 10.6 (4.5–24.8) 1.0 (0.9–1.0) 74.1 (53.7–88.9) 79.5 (77.6–81.4) 0.07 (79.4%)
Overall
P-value**
9.3 (7.4–11.4)
Χ2m = 782.0, p < 0.001
98.7 (98.2–99.1)
Χ2m = 34.0, p < 0.001
7.4 (5.0–10.92)
-
0.9 (0.9–0.9)
-
70.2 (60.9–78.4)
-
77.3 (75.9–78.7)
-
0.11 (77.1%)
Z = 11.6, p < 0.001
  1. PPV positive predictive value, NPV negative predictive value, LR+ positive likelihood ratio, LR negative likelihood ratio
  2. **Obtained from McNemar’s chi-square (Χ2m) test (sensitivity & specificity) / Weighted generalized score chi-square test (PPV & NPV)