TABLE 3.
Performance of QFT-GIT and QFT-Plus for definite LTBI according to different characteristicsa
| Characteristic | No. of patients |
Performance (% [95% confidence interval]) |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Definite LTBI and test result that was: |
Not definite LTBI and test result that was: |
||||||||
| Positive | Negative | Positive | Negative | Sensitivity | Specificity | PPV | NPV | Accuracy | |
| QFT-GITb | |||||||||
| All | 59 | 7 | 7 | 156 | 89.4 (79.4–95.6) | 95.7 (91.4–98.3) | 89.4 (79.4–95.6) | 95.7 (91.4–98.3) | 93.9 (90.0–96.6) |
| Age (yr) | |||||||||
| 60–64 | 3 | 0 | 2 | 4 | 100.0 (29.2–100.0) | 66.7 (22.3–95.7) | 60.0 (14.7–94.7) | 100.0 (39.8–100.0) | 77.8 (40.0–97.2) |
| 65–74 | 10 | 1 | 1 | 22 | 90.9 (58.7–99.8) | 95.7 (78.1–99.9) | 90.9 (58.7–99.8) | 95.7 (78.1–99.9) | 94.1 (80.3–99.3) |
| 75–84 | 28 | 2 | 3 | 75 | 93.3 (77.9–99.2) | 96.2 (89.2–99.2) | 90.3 (74.2–98.0) | 97.4 (90.9–99.7) | 95.4 (89.5–98.5) |
| ≥85 | 18 | 4 | 1 | 55 | 81.8 (59.7–94.8) | 98.2 (90.4–100.0) | 94.7 (74.0–99.9) | 93.2 (83.5–98.1) | 93.6 (85.7–97.9) |
| Sex | |||||||||
| Female | 26 | 3 | 3 | 80 | 89.7 (72.6–97.8) | 96.4 (89.8–99.2) | 89.7 (72.6–97.8) | 96.4 (89.8–99.2) | 94.6 (88.7–98.0) |
| Male | 33 | 4 | 4 | 76 | 89.2 (74.6–97.0) | 95.0 (87.7–98.6) | 89.2 (74.6–97.0) | 95.0 (87.7–98.6) | 93.2 (87.0–97.0) |
| Albumin (g/dl) | |||||||||
| <3.5 | 10 | 2 | 2 | 43 | 83.3 (51.6–97.9) | 95.6 (84.9–99.5) | 83.3 (51.6–97.9) | 95.6 (84.9–99.5) | 93.0 (83.0–98.1) |
| ≥3.5 | 49 | 5 | 5 | 113 | 90.7 (79.7–96.9) | 95.8 (90.4–98.6) | 90.7 (79.7–96.9) | 95.8 (90.4–98.6) | 94.2 (89.6–97.2) |
| Creatinine (mg/dl) | |||||||||
| <1.5 | 52 | 7 | 5 | 135 | 88.1 (77.1–95.1) | 96.4 (91.9–98.8) | 91.2 (80.7–97.1) | 95.1 (90.1–98.0) | 94.0 (89.7–96.8) |
| ≥1.5 | 7 | 0 | 2 | 21 | 100.0 (59.0–100.0) | 91.3 (72.0–98.9) | 77.8 (40.0–97.2) | 100.0 (83.9–100.0) | 93.3 (77.9–99.2) |
| HbA1C (%) | |||||||||
| <6.5 | 51 | 6 | 5 | 127 | 89.5 (78.5–96.0) | 96.2 (91.4–98.8) | 91.1 (80.4–97.0) | 95.5 (90.4–98.3) | 94.2 (89.8–97.1) |
| ≥6.5 | 8 | 1 | 2 | 29 | 88.9 (51.8–99.7) | 93.5 (78.6–99.2) | 80.0 (44.4–97.5) | 96.7 (82.8–99.9) | 92.5 (79.6–98.4) |
| Diabetes mellitus | |||||||||
| No | 45 | 5 | 5 | 100 | 90.0 (78.2–96.7) | 95.2 (89.2–98.4) | 90.0 (78.2–96.7) | 95.2 (89.2–98.4) | 93.5 (88.5–96.9) |
| Yes | 14 | 2 | 2 | 56 | 87.5 (61.7–98.4) | 96.6 (88.1–99.6) | 87.5 (61.7–98.4) | 96.6 (88.1–99.6) | 94.6 (86.7–98.5) |
| QFT-Plusc | |||||||||
| All | 66 | 0 | 8 | 155 | 100.0 (94.6–100.0) | 95.1 (90.6–97.9) | 89.2 (79.8–95.2) | 100.0 (97.6–100.0) | 96.5 (93.2–98.5) |
| Age (yr) | |||||||||
| 60–64 | 3 | 0 | 0 | 6 | 100.0 (29.2–100.0) | 100.0 (54.1–100.0) | 100.0 (29.2–100.0) | 100.0 (54.1–100.0) | 100.0 (66.4–100.0) |
| 65–74 | 11 | 0 | 0 | 23 | 100.0 (71.5–100.0) | 100.0 (85.2–100.0) | 100.0 (71.5–100.0) | 100.0 (85.2–100.0) | 100.0 (89.7–100.0) |
| 75–84 | 30 | 0 | 7 | 71 | 100.0 (88.4–100.0) | 91.0 (82.4–96.3) | 81.1 (64.8–92.0) | 100.0 (94.9–100.0) | 93.5 (87.1–97.4) |
| ≥85 | 22 | 0 | 1 | 55 | 100.0 (84.6–100.0) | 98.2 (90.4–100.0) | 95.7 (78.1–99.9) | 100.0 (93.5–100.0) | 98.7 (93.1–100.0) |
| Sex | |||||||||
| Female | 29 | 0 | 2 | 81 | 100.0 (88.1–100.0) | 97.6 (91.6–99.7) | 93.5 (78.6–99.2) | 100.0 (95.5–100.0) | 98.2 (93.7–99.8) |
| Male | 37 | 0 | 6 | 74 | 100.0 (90.5–100.0) | 92.5 (84.4–97.2) | 86.0 (72.1–94.7) | 100.0 (95.1–100.0) | 94.9 (89.2–98.1) |
| Albumin (g/dl) | |||||||||
| <3.5 | 12 | 0 | 4 | 41 | 100.0 (73.5–100.0) | 91.1 (78.8–97.5) | 75.0 (47.6–92.7) | 100.0 (91.4–100.0) | 93.0 (83.0–98.1) |
| ≥3.5 | 54 | 0 | 4 | 114 | 100.0 (93.4–100.0) | 96.6 (91.5–99.1) | 93.1 (83.3–98.1) | 100.0 (96.8–100.0) | 97.7 (94.2–99.4) |
| Creatinine (mg/dl) | |||||||||
| <1.5 | 59 | 0 | 5 | 135 | 100.0 (93.9–100.0) | 96.4 (91.9–98.8) | 92.2 (82.7–97.4) | 100.0 (97.3–100.0) | 97.5 (94.2–99.2) |
| ≥1.5 | 7 | 0 | 3 | 20 | 100.0 (59.0–100.0) | 87.0 (66.4–97.2) | 70.0 (34.8–93.3) | 100.0 (83.2–100.0) | 90.0 (73.5–97.9) |
| HbA1C (%) | |||||||||
| <6.5 | 57 | 0 | 7 | 125 | 100.0 (93.7–100.0) | 94.7 (89.4–97.8) | 89.1 (78.8–95.5) | 100.0 (97.1–100.0) | 96.3 (92.5–98.5) |
| ≥6.5 | 9 | 0 | 1 | 30 | 100.0 (66.4–100.0) | 96.8 (83.3–99.9) | 90.0 (55.5–99.7) | 100.0 (88.4–100.0) | 97.5 (86.8–99.9) |
| Diabetes mellitus | |||||||||
| No | 50 | 0 | 6 | 99 | 100.0 (92.9–100.0) | 94.3 (88.0–97.9) | 89.3 (78.1–96.0) | 100.0 (96.3–100.0) | 96.1 (91.8–98.6) |
| Yes | 16 | 0 | 2 | 56 | 100.0 (79.4–100.0) | 96.6 (88.1–99.6) | 88.9 (65.3–98.6) | 100.0 (93.6–100.0) | 97.3 (90.6–99.7) |
a
LTBI, latent TB infection.
b
QFT-GIT, QuantiFERON-TB Gold In-Tube.
c
QFT-Plus, QuantiFERON-TB Gold Plus.