Table 5. Effect of age on the clinical diagnosis for influenza.
| Symptoms/Case definitions | Mild-ARI, age < 60 years |
Severe-ARI, age < 60 years |
Severe-ARI, age ≥ 60 years |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Influenza | Non-influenza | P value | Influenza | Non-influenza | P value | Influenza | Non-influenza | P value | |
| n = 74 | n = 112 | — | n = 70 | n = 43 | — | n = 39 | n = 51 | — | |
| Cough | 66 (89.2) | 98 (87.5) | 0.819 | 68 (97.1) | 42 (97.7) | 1.000 | 39 (100) | 51 (100) | 1.000 |
| Sore throat | 49 (66.2) | 92 (82.1) | 0.015 | 38 (54.3) | 26 (60.5) | 0.562 | 14 (35.9) | 20 (39.2) | 0.828 |
| Breathlessness | 5 (6.8) | 13 (11.6) | 0.320 | 29 (41.4) | 23 (53.5) | 0.246 | 21 (53.8) | 32 (62.7) | 0.517 |
| Runny nose | 40 (54.1) | 100 (89.3) | <0.001 | 39 (55.7) | 30 (69.8) | 0.166 | 16 (41) | 28 (54.9) | 0.209 |
| T ≥ 37.5 °C | 60 (81.1) | 19 (17) | <0.001 | 59 (84.3) | 20 (46.5) | <0.001 | 20 (51.3) | 19 (37.3) | 0.204 |
| T ≥ 37.8 °C | 50 (67.6) | 12 (10.7) | <0.001 | 56 (80) | 19 (44.2) | <0.001 | 20 (51.3) | 17 (33.3) | 0.130 |
| T ≥ 38.0 °C | 41 (55.4) | 10 (8.9) | <0.001 | 54 (77.1) | 19 (44.2) | <0.001 | 18 (46.2) | 13 (25.5) | 0.047 |
| FRI | 69 (93.2) | 38 (33.9) | <0.001 | 66 (94.3) | 33 (76.7) | 0.008 | 34 (87.2) | 37 (72.5) | 0.120 |
| ILI-U | 49 (66.2) | 12 (10.7) | <0.001 | 54 (77.1) | 19 (44.2) | <0.001 | 20 (51.3) | 17 (33.3) | 0.130 |
| ILI-W | 36 (48.6) | 10 (8.9) | <0.001 | 48 (68.6) | 14 (32.6) | <0.001 | 16 (41.0) | 10 (19.6) | 0.035 |