Systemic and respiratory symptoms among cases and controls
| Influenza test result | |||||
| Influenza-positive n=72 44.2% | Influenza-negative n=91 55.8% | p Value | |||
| Respiratory symptoms | |||||
| Cough | 72 | 100.0 | 83 | 91.2 | 0.01 |
| Sore throat | 43 | 60.6 | 45 | 50.0 | 0.40 |
| Shortness of breath | 34 | 47.2 | 70 | 76.9 | <0.001 |
| Systemic symptoms | |||||
| Fever | 70 | 97.2 | 82 | 90.2 | 0.11 |
| Malaise | 71 | 100.0 | 90 | 98.9 | 0.36 |
| Myalgia | 46 | 65.7 | 48 | 53.3 | 0.21 |
| Headache | 56 | 78.9 | 71 | 78.0 | 0.53 |
| Sudden onset of symptoms | 68 | 94.4 | 79 | 86.8 | 0.12 |
| Deterioration of general condition | 48 | 66.7 | 86 | 94.5 | <0.001 |
| Deterioration of functional status (Barthel index<100) | 15 | 21.1 | 41 | 45.1 | 0.06 |