Table 3.
Indicators of diagnostic test performance
| Testa | Resultb |
|||||
|---|---|---|---|---|---|---|
| Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | LR+ | LR− | |
| ≥1 positive result | ||||||
| PCRm | 57.7 (37.2–76) | 94.4 (70.6–99.7) | 93.8 (67.7–99.7) | 60.7 (40.7–77.9) | 10.4 (1.33–81.1) | 0.45 (0.37–0.54) |
| PCRr | 50 (30.4–69.6) | 66.7 (41.2–85.6) | 68.4 (43.5–86.4) | 48 (28.3–68.2) | 1.50 (0.93–2.42) | 0.75 (0.59–0.95) |
| PCRm-PCRr | 65.4 (44.4–82.1) | 66.7 (41.2–85.6) | 73.9 (51.3–88.9) | 57.1 (34.4–77.4) | 1.96 (1.33–2.89) | 0.52 (0.38–0.70) |
| ≥2 positive results | ||||||
| PCRm | 53.8 (33.7–72.9) | 100 (78.1–100) | 100 (73.2–100) | 60 (40.7–76.8) | 0.46 (0.39–0.54) | |
| PCRr | 46.2 (27.1–66.3) | 100 (78.1–100) | 100 (69.9–100) | 56.3 (37.9–73.2) | 0.54 (0.47–0.62) | |
| PCRm-PCRr | 65.4 (44.4–82.1) | 94.4 (70.6–99.7) | 94.4 (70.6–99.7) | 65.4 (44.4–82.1) | 11.8 (1.56–88.8) | 0.37 (0.29–0.46) |
a
PCRm, mitochondrial PCR; PCRr, ribosomal PCR; PCRm-PCRr, combination of both PCR assays.
b
PPV, positive predictive value; NPV, negative predictive value; LR+, likelihood ratio of a positive test; LR−, likelihood ratio of a negative test. The 95% CI is in parentheses.