Table 4. Diagnostic values of the QFT-GIT and TST for active tuberculosis assessed in PTB patients and disease controls.
| Category | Test | % Sensitivity (95% CI) | % Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | LR1 | LR2 |
|---|---|---|---|---|---|---|---|
| All PTB patients | |||||||
| QFT-GIT | 80.9 (75.9–85.2) | 36.6 (22.1–53.1) | 90.3 (86.1–93.5) | 20.8 (12.2–32.0) | 1.275 | 1.916 | |
| TST 5 mm | 86.2 (81.7–90.0) | 26.8 (14.2–42.9) | 89.1 (84.7–92.5) | 22.0 (11.5–36.0) | 1.178 | 1.942 | |
| TST 10 mm | 79.5 (74.3–84.4) | 36.6 (22.1–53.1) | 89.6 (85.2–93.1) | 20.6 (12.0–31.6) | 1.256 | 1.785 | |
| TST 15 mm | 59.4 (53.4–65.1) | 61.0 (44.5–75.8) | 91.3 (86.3–95.0) | 17.9 (11.9–25.2) | 1.521 | 1.502 | |
| Heilongjiang | |||||||
| QFT-GIT | 75.3 (67.6–82.0) | 36.6 (22.1–53.1) | 81.3 (73.8–87.4) | 28.7 (17.1–43.1) | 1.188 | 1.482 | |
| TST 5 mm | 72.2 (63.8–79.6) | 26.8 (14.2–42.9) | 76.2 (67.8–83.3) | 22.9 (12.0–37.3) | 0.9865 | 0.982 | |
| TST 10 mm | 59.4 (50.5–67.8) | 36.6 (22.1–53.1) | 75.2 (65.9–83.1) | 21.7 (12.7–33.3) | 0.9367 | 0.901 | |
| TST 15 mm | 25.6 (18.4–33.9) | 61.0 (44.5–75.8) | 68.0 (53.3–80.5) | 20.2 (13.5–28.3) | 0.6551 | 0.820 | |
| Zhejiang | |||||||
| QFT-GIT | 86.5 (79.9–91.6) | 36.6 (22.1–53.1) | 83.1 (76.3–88.7) | 42.9 (26.7–60.1) | 1.364 | 2.711 | |
| TST 5 mm | 98.7 (95.3–99.8) | 26.8 (14.2–42.9) | 83.1 (76.3–88.3) | 84.6 (54.6–98.1) | 1.348 | 20.615 | |
| TST 10 mm | 97.3 (93.3–99.2) | 36.6 (22.1–53.1) | 84.9 (78.6–89.9) | 79.0 (54.4–94.0) | 1.535 | 13.556 | |
| TST 15 mm | 89.3 (83.3–93.8) | 61.0 (44.5–75.8) | 89.3 (83.3–93.8) | 61.0 (44.5–75.3) | 2.289 | 5.701 | |
Footnotes: % Sensitivity: percentage of positive, calculated with available QFT-GIT and TST results; 95% CI: Confidence interval; % Specificity: percentage of negative, calculated with available QFT-GIT and TST results; PPV, positive predictive value; NPV, negative predictive value; LR1, likelihood ratio for a positive test; LR2, likelihood ratio for a negative test QFT-GIT: QuantiFERON-TB G In-tube; TST: tuberculin skin test; PTB: pulmonary tuberculosis.