Table 3. Clinical signs and symptoms associated with laboratory-confirmed influenza, stratified by age group, GROG study, France, 2009–2014 (n = 14,994).
| Variable | 0–4 years (n = 5,521) |
5–14 years (n = 3,582) |
15–64 years (n = 5,338) |
≥ 65 years (n = 553) |
Total (n = 14,994) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | P value | OR | 95% CI | p value | OR | 95% CI | P value | OR | 95% CI | P value | OR | 95% CI | p value | |
| Sex | |||||||||||||||
| Male | Reference | Reference | Reference | Reference | Reference | ||||||||||
| Female | NS | NS | NS | NS | NS | ||||||||||
| Temperature group (°C) | |||||||||||||||
| T < 38 | Reference | Reference | Reference | Reference | Reference | ||||||||||
| 38 ≤ T < 38.5 | NS | NS | 1.37 | 1.05–1.81 | 0.023 | NS | 1.30 | 1.05–1.62 | 0.015 | ||||||
| 38.5 ≤ T < 39 | 2.78 | 1.33–5.81 | 0.006 | 1.55 | 1.02–2.34 | 0.039 | 2.20 | 1.68–2.89 | <0.001 | 2.08 | 1.11–3.92 | 0.023 | 1.96 | 1.61–2.40 | <0.001 |
| T ≥ 39 | 3.55 | 1.74–7.22 | <0.001 | 2.05 | 1.34–3.16 | 0.001 | 2.69 | 2.07–3.50 | <0.001 | 3.18 | 1.54–6.58 | 0.002 | 2.27 | 1.85–2.79 | <0.001 |
| Clinical parameters | |||||||||||||||
| Cough | 1.41 | 1.17–1.69 | <0.001 | 3.27 | 2.71–3.96 | <0.001 | 3.72 | 3.01–4.60 | <0.001 | 3.93 | 1.92–8.05 | <0.001 | 2.40 | 2.11–2.72 | <0.001 |
| Headache | 1.65 | 1.43–1.92 | <0.001 | 1.23 | 1.06–1.43 | <0.001 | NS | NS | 1.65 | 1.51–1.81 | <0.001 | ||||
| Weakness | 1.59 | 1.36–1.85 | <0.001 | 1.55 | 1.33–1.80 | <0.001 | 1.36 | 1.09–1.68 | 0.006 | 1.64 | 1.05–2.57 | 0.030 | 1.71 | 1.54–1.90 | <0.001 |
| Chills | 1.38 | 1.21–1.60 | <0.001 | 1.33 | 1.15–1.54 | <0.001 | 1.76 | 1.52–2.04 | <0.001 | NS | 1.57 | 1.44–1.71 | <0.001 | ||
| Myalgia | 1.55 | 1.32–1.82 | <0.001 | 1.26 | 1.10–1.44 | 0.001 | 1.26 | 1.03–1.55 | 0.025 | NS | 1.49 | 1.36–1.64 | <0.001 | ||
| Coryza/rhinitis | NS | 1.39 | 1.19–1.62 | 0.001 | 1.24 | 1.07–1.45 | 0.005 | NS | 1.12 | 1.02–1.23 | 0.022 | ||||
| Conjunctivitis | NS | NS | 1.27 | 1.02–1.59 | 0.032 | NS | NS | ||||||||
| Gastrointestinal symptoms | 1.19 | 1.03–1.38 | 0.018 | NS | NS | NS | NS | ||||||||
| Adenopathy | NS | NS | 0.74 | 0.59–0.93 | 0.010 | NS | NS | ||||||||
| Pharyngitis | 0.81 | 0.70–0.94 | 0.006 | 0.81 | 0.70–0.94 | 0.005 | 0.85 | 0.75–0.96 | 0.010 | NS | 0.84 | 0.77–0.91 | <0.001 | ||
| Shortness of breath | 0.43 | 0.31–0.61 | <0.001 | NS | NS | NS | 0.74 | 0.64–0.86 | <0.001 | ||||||
| Otitis/otalgia | 0.68 | 0.57–0.81 | <0.001 | 0.70 | 0.53–0.92 | 0.010 | NS | NS | 0.66 | 0.59–0.75 | <0.001 | ||||
| Bronchitis | 0.36 | 0.28–0.47 | <0.001 | NS | 1.33 | 1.03–1.71 | 0.028 | NS | 0.66 | 0.54–0.81 | <0.001 | ||||
| Rash | 0.34 | 0.17–0.71 | 0.004 | NS | NS | NS | 0.46 | 0.29–0.71 | 0.001 | ||||||
CI: confidence interval; GROG: Groupes Régionaux d’Observation de la Grippe; NS: statistically not significant; OR: odds ratio; T: temperature.