Table 2.
Performance of rapid influenza diagnostic tests compared to PCR-based detection of influenza A virus.
| Test | Influenza | Sensitivity (%) (95% CI) | Specificity (%) (95% CI) | PPV (%) (95% CI) | NPV (%) (95% CI) |
|---|---|---|---|---|---|
| Sofia Influenza A + B FIA | Influenza A | 145/196, 74.0 (67.3–80.0) | 186/195, 95.4 (91.4–97.9) | 145/154, 94.2 (89.2–97.3) | 186/237, 78.5 (72.7–83.5) |
| 18–49 yearsa | 101/132, 76.5 (68.4–83.5) | 103/109, 94.5 (88.4–97.9) | 101/107, 94.4 (88.2–97.9) | 103/134, 76.9 (68.8–83.7) | |
| ≥50 yearsa | 44/64, 68.8 (55.9–79.8) | 83/86, 96.5 (90.1–99.2) | 44/47, 93.6 (82.4–98.6) | 83/103, 80.6 (71.6–87.7) | |
| ≤2 daysb | 127/164, 77.4 (70.3–83.6) | 144/151, 95.4 (90.7–98.1) | 127/134, 94.8 (89.5–97.9) | 144/181, 79.6 (72.9–85.2) | |
| >2 daysb | 18/32, 56.3 (37.7–73.6) | 42/44, 95.5 (84.5–99.3) | 18/20, 90.0 (68.3–98.5) | 42/56, 75.0 (61.6–85.6) | |
| H3N2 | 110/149, 73.8 (66.0–80.7) | 186/195, 95.4 (91.4–97.9) | 110/119, 92.4 (86.1–96.5) | 186/225, 82.7 (77.1–87.4) | |
| 18–49 yearsa | 71/94, 75.5 (65.6–83.8) | 103/109, 94.5 (88.4–97.9) | 71/77, 92.2 (83.8–97.1) | 103/126, 81.8 (73.9–88.1) | |
| ≥50 yearsa | 39/55, 70.9 (57.1–82.4) | 83/86, 96.5 (90.1–99.2) | 39/42, 92.9 (80.5–98.4) | 83/99, 83.8 (75.1–90.5) | |
| ≤2 daysb | 101/132, 76.5 (68.4–83.5) | 144/151, 95.4 (90.7–98.1) | 101/108, 93.5 (87.1–97.3) | 144/175, 82.3 (75.8–87.6) | |
| >2 daysb | 9/17, 52.9 (27.9–77.0) | 42/44, 95.5 (84.5–99.3) | 9/11, 81.8 (48.2–97.2) | 42/50, 84.0 (70.9–92.8) | |
| SD Bioline Influenza Ag A/B/A(H1N1/2009) | Influenza A | 106/196, 54.1 (46.8–61.2) | 187/195, 95.9 (92.1–98.2) | 106/114, 93.0 (86.6–96.9) | 187/277, 67.5 (61.7–73.0) |
| 18–49 yearsa | 73/132, 55.3 (46.4–64.0) | 105/109, 96.3 (90.9–99.0) | 73/77, 94.8 (87.2–98.5) | 105/164, 64.0 (56.2–71.4) | |
| ≥50 yearsa | 33/64, 51.6 (38.7–64.3) | 82/86, 95.4 (88.5–98.7) | 33/37, 89.2 (74.6–96.9) | 82/113, 72.6 (63.4–80.5) | |
| ≤2 daysb | 98/164, 59.8 (51.8–67.3) | 144/151, 95.4 (90.7–98.1) | 98/105, 93.3 (86.7–97.3) | 144/210, 68.6 (61.8–74.8) | |
| >2 daysb | 8/32, 25.0 (11.5–43.4) | 43/44, 97.7 (87.9–99.6) | 8/9, 88.9 (51.7–98.2) | 43/67, 64.2 (51.5–75.5) | |
| H3N2 | 85/149, 57.1 (48.7–65.1) | 187/195, 95.9 (92.1–98.2) | 85/93, 91.4 (83.8–96.2) | 187/251, 74.5 (68.6–79.8) | |
| 18–49 yearsa | 54/94, 57.5 (46.8–67.6) | 105/109, 96.3 (90.9–99.0) | 54/58, 93.1 (83.3–98.1) | 105/145, 72.4 (64.4–79.5) | |
| ≥50 yearsa | 31/55, 56.4 (42.3–69.7) | 82/86, 95.4 (88.5–98.7) | 31/35, 88.6 (73.2–96.7) | 82/106, 77.4 (68.2–84.9) | |
| ≤2 daysb | 81/132, 61.4 (52.5–69.7) | 144/151, 95.4 (90.7–98.1) | 81/88, 92.1 (84.3–96.7) | 144/195, 73.9 (67.1–79.9) | |
| >2 daysb | 4/17, 23.5 (7.0–49.9) | 43/44, 97.7 (87.9–99.6) | 4/5, 80.0 (28.8–96.7) | 43/56, 76.8 (63.6–87.0) |
a
Patient's age.
b
Time to hospital visit from symptom onset.