Table 3.
Statistical performance of different types of samples (n = 297, composite standard).
| Sample type | TP | FP | TN | FN | PPA | NPA | PPV | NPV |
|---|---|---|---|---|---|---|---|---|
| BALF | 30 | 5 | 5 | 0 | 100.0 (85.9–100) |
50.0 (20.1–79.9) |
85.7 (69.0–94.6) |
100 (46.3–100) |
| Sputum | 31 | 3 | 2 | 0 | 100.0 (86.3–100) |
40.0 (7.3–83.0) |
91.2 (75.2–97.7) |
100 (19.8–100) |
| Urine | 17 | 6 | 1 | 0 | 100.0 (77.1–100) |
14.3 (0.8–58.0) |
73.9 (51.3–88.9) |
100 (5.5–100) |
| Abscess | 22 | 0 | 1 | 1 | 95.7 (76.0–99.8) |
100.0 (5.5–100) |
100 (81.5–100) |
50.0 (2.7–97.3) |
| Plasma | 45 | 17 | 34 | 13 | 77.6 (64.4–87.1) |
66.7 (52.0–78.9) |
72.6 (59.6–82.8) |
72.3 (57.1–83.9) |
| CSF | 15 | 1 | 22 | 2 | 88.2 (62.3–97.9) |
95.7 (76.0–99.8) |
93.8 (67.7–99.7) |
91.7 (71.5–98.5) |
| SCE | 5 | 3 | 13 | 3 | 62.5 (25.9–89.8) |
81.3 (53.7–95.0) |
62.5 (25.9–89.8) |
81.3 (53.7–95.0) |
| Total | 165 | 35 | 78 | 19 | 89.7 (84.1–93.5) |
69.0 (59.5–77.2) |
82.5 (76.4–87.4) |
80.4 (70.9–87.5) |
TP, FP, FN, and TN were shown as numbers of tests. PPA, NPA, PPV, and NPV were shown as % (95% confidence intervals) and were calculated with http://vassarstats.net/clin1.html#return.