Table 5. Sensitivity, specificity and predictive values of signs and symptoms for influenza virus positivity among HIV-uninfected and HIV-infected children aged <5 years hospitalised with severe respiratory illness at the Edendale and Klerksdorp hospitals, South Africa, 2011–2015.
| Value (%) and 95% Confidence Interval | ||||||||
|---|---|---|---|---|---|---|---|---|
| HIV uninfected | HIV infected | |||||||
| Sensitivity | Specificity | PPV* | NPV** | Sensitivity | Specificity | PPV* | NPV** | |
| Individual clinical signs and symptoms | ||||||||
| Fever >38°C | 54 (43–64) | 66 (64–68) | 8 (6–10) | 96 (95–97) | 44 (20–70) | 55 (50–61) | 5 (2–10) | 95 (91–98) |
| Any fever | 74 (64–82) | 39 (37–41) | 6 (5–8) | 96 (95–98) | 63 (27–85) | 32 (27–39) | 5 (2–9) | 194 (88–98) |
| Cough | 95 (89–98) | 7 (6–8) | 6 (5–7) | 96 (92–99) | 100 (79–100) | 6 (3–9) | 5 (3–9) | 100 (80–100) |
| Difficulty breathing | 62 (52–72) | 31 (29–33) | 5 (4–6) | 94 (91–95) | 56 (30–80) | 34 (29–40) | 4 (2–8) | 94 (87–97) |
| Diarrhoea | 18 (11–27) | 87 (85–88) | 7 (5–11) | 95 (94–96) | 38 (15–65) | 78 (73–83) | 8 (3–17) | 96 (93–98) |
| Vomiting | 6 (2–12) | 96 (95–97) | 7 (3–11) | 95 (94–96) | 19 (4–47) | 94 (90–96) | 14 (3–35) | 96 (93–98) |
| No feeding | 18 (12–27) | 85 (83–87) | 6 (4–10) | 95 (94–96) | 13 (2–38) | 85 (81–89) | 4 (1–15) | 95 (92–97) |
| Lethargy | 41 (31–51) | 57 (55–60) | 5 (4–7) | 94 (93–96) | 44 (20–70) | 49 (43–55) | 4 (2–9) | 94 (89–97) |
| Convulsion | 9 (4–16) | 96 (95–97) | 12 (6–22) | 95 (94–96) | 6 (0.2–30) | 98 (96–100) | 17 (0.4–64) | 95 (92–97) |
| Stridor | 17 (10–25) | 73 (71–75) | 3 (2–6) | 93 (94–95) | 25 (7–52) | 76 (71–81) | 5 (2–13) | 95 (92–97) |
| Symptoms duration in days | ||||||||
| ≤7 | 92 (86–96) | 5 (4–6) | 6 (5–8) | 90 (82–95) | 90 (75–97) | 6 (3–8) | 12 (8–16) | 75 (48–93) |
| ≤10 | 92 (85–97) | 5 (4–6) | 5 (4–6) | 93 (86–97) | 90 (74–98) | 5 (3–8) | 10 (7–14) | 81 (54–96) |
| ≤14 | 92 (83–98) | 5 (4–6) | 3 (3–4) | 95 (89–98) | 91 (69–99) | 5 (3–8) | 7 (4–10) | 88 (62–98) |
*PPV: positive predictive value
**NPV: negative predictive value