Table 2.
Distribution of severity indicators by flu season. Values given in per cent, with number of illness episodes in parentheses
| Percentage of individuals per category in each year (No.) | |||||
|---|---|---|---|---|---|
| 2011–12 | 2012–13 | 2013–14 | 2014–15 | Combined | |
| Symptoms | |||||
| ARI | 45 (586/1302) | 32.3 (951/2947) | 41.2 (1049/2544) | 33.1 (887/2677) | 36.7 (3473/9470) |
| ILI–No fever | 33.2 (432/1302) | 31.4 (925/2947) | 36.4 (926/2544) | 32.2 (863/2677) | 33.2 (3146/9470) |
| ILI-Fever | 13.4 (175/1302) | 21.1 (623/2947) | 13.8 (352/2544) | 21.1 (564/2677) | 18.1 (1714/9470) |
| ILI-Fever, with phlegm | 8.4 (109/1302) | 15.2 (448/2947) | 8.5 (217/2544) | 13.6 (363/2677) | 12 (1137/9470) |
| Duration (days) | |||||
| 0–3 | 56.2 (732/1302) | 50.9 (1501/2947) | 56.9 (1443/2537) | 51 (1364/2676) | 53.3 (5040/9462) |
| 4–7 | 26.8 (349/1302) | 28.3 (834/2947) | 24.5 (622/2537) | 28.1 (752/2676) | 27 (2557/9462) |
| 8–14 | 11.8 (154/1302) | 13 (384/2947) | 12.7 (322/2537) | 12.8 (343/2676) | 12.7 (1203/9462) |
| ≥ 15 | 5.2 (67/1302) | 7.7 (228/2947) | 5.9 (150/2537) | 8.1 (217/2676) | 7 (662/9462) |
| Health-score decrease | |||||
| 0–10% | - | 21.5 (463/2153) | 26.3 (573/2181) | 22 (536/2440) | 23.2 (1572/6774) |
| 10.1-% | - | 21.7 (468/2153) | 24.5 (535/2181) | 25.3 (618/2440) | 23.9 (1621/6774) |
| 20.1–30% | - | 16.1 (347/2153) | 17.8 (388/2181) | 15.7 (382/2440) | 16.5 (1117/6774) |
| 30.1–50% | - | 22.4 (483/2153) | 21.2 (463/2181) | 21.6 (527/2440) | 21.7 (1473/6774) |
| ≥ 50.1% | - | 18.2 (392/2153) | 10.2 (222/2181) | 15.5 (377/2440) | 14.6 (991/6774) |