Table 3 Diagnostic performance of clinical characteristics associated with a definitive diagnosis of influenza.
Characteristic | Sensitivity | Specificity | Positive predictive value | Negative predictive value | AUC (95% CI) |
|---|---|---|---|---|---|
N = 520 | |||||
Disease course | |||||
≥1 day | 45.4% | 43.8% | 46.8% | 42.4% | |
Cough | 67.5% | 44.2% | 56.8% | 55.6% | |
Productive cough | 33.6% | 74.3% | 58.7% | 50.7% | |
Runny nose | 37.6% | 75.5% | 62.6% | 52.7% | |
Chills | 35.1% | 76.3% | 61.7% | 51.9% | |
Colloidal test (n = 424) | 73.1% | 67.2% | 74.0% | 66.1% | |
Influenza A test | 52.9% | 74.2% | 72.4% | 55.2% | |
Influenza B test | 20.6% | 92.5% | 77.8% | 47.7% | |
Routine blood tests, white blood cell count (WBC) (n = 490) | 0.604 (0.553–0.656) | ||||
WBC < 10 × 109/L | 89.7% | 31.2% | 58.2% | 74.0% | |
Neutrophil % | 0.570 (0.519–0.621) | ||||
<75% | 71.9% | 40.9% | 56.5% | 57.7% | |
Lymphocyte % | 0.557 (0.502–0.612) | ||||
<20% | 51.4% | 38.4% | 47.1% | 42.5% | |
Monocyte % | 0.608 (0.554–0.662) | ||||
>10% | 63.2% | 57.0% | 61.1% | 59.2% | |
