Table 3 Diagnostic indices of the direct-sample PCRs for the detection and identification of dermatophytes from ringworm lesions based on (a) culture and (b) culture and/or nested PCR as the gold standards
Diagnostic indexa | Pan-dermatophyte | One step-PCR | Nested PCR | Â |
|---|---|---|---|---|
Culture as the gold standard | Â | |||
 Se (95% CI) | 82.14% (72.26–89.65) | 71.43% (60.53–80.76) | 92.86% (85.10–97.33) |  |
 SP (95% CI) | 72.73% (60.36–82.97 | 50% (37.43–62.57) | 54.55% (41.81–66.86) |  |
 PPV (95% CI) | 79.31% (71.86–85.20) | 64.52% (57.96–70.57) | 72.22% (66.48–77.32) |  |
 NPV (95% CI) | 76.19% (66.40–83.82) | 57.89% (47.58–67.56) | 85.71% (72.91–93.05) |  |
 LR+(95% CI | 3.01 (2.01–4.52) | 1.43 (1.08–1.88) | 2.04 (1.56–2.68) |  |
 LR- (95% CI) | 0.25 (0.15–0.40) | 0.57 (0.38–0.87) | 0.13 (0.06–0.29) |  |
 DOR (95% CI) | 12.36 (5.64–26.7) | 2.5 (1.72–4.19) | 15.6 (5.965–40.799) |  |
 AUC | 78% (70.51–84.35) | 62% (53.72–69.79) | 76% (68.35–82.59) |  |
 Kappa value | 0.55*** | 0.217 ** | 0.493*** |  |
| Â | Direct microscopy | Culture | One step-PCR | Nested PCR |
Nested PCR and Culture as the gold standard | ||||
 Se (95% CI) | 78.95% (70.31–86.02) | 73.68% (64.61–81.49) | 63.16% (53.61–72.00) | 94.74% (88.90–8.04) |
 SP (95% CI) | 41.67% (25.51–59.24) | 100% (90.26–100) | 41.67% (25.51–59.24) | 100% (90.26–100) |
 PPV (95% CI) | 81.08% (76.19–85.16) | 100% | 77.42% (71.56–82.37) | 100% |
 NPV (95% CI) | 38.46% (26.99–51.38) | 54.55% (46.88–62) | 26.32% (18.47–36.02) | 85.71% (73.36–92.89) |
 LR+(95% CI | 1.35 (1.01–1.81) | b | 1.08 (0.79–1.48) | b |
 LR- (95% CI) | 0.51 (0.30–0.85) | 0.26 (0.19–0.36) | 0.88 (0.56–1.39) | 0.05 (0.02–0.11) |
 DOR (95% CI) | 2.68 (1.2–5.9) | 0.46 (0.35–0.59) | 1.22 (0.57–2.62) | 19.6 (8.7–41.4) |
 AUC | 70% (61.99–77.20) | 80% (72.70–86.08) | 58% (49.68–66) | 96% (91.50–98.52) |
 Kappa value | 0.2 ** | 0.57** | 0.04 | 0.91*** |