Table 4.
Crude and adjusted odds ratio (OR) and 95% confidence intervals (95% CI) for severe and mild influenza-like illness (ILI) by season, among those with a Charlson Comorbidity Index score of zero (0)
| Influenza season | BMI category | Severe ILI | Mild ILI | ||
|---|---|---|---|---|---|
| Crude OR | Adjusted OR | Crude OR | Adjusted OR | ||
| 2003–2004 | Overweight | 1·12 (0·64, 1·97) | 0·90 (0·51, 1·59) | 0·92 (0·81, 1·05) | 0·98 (0·85, 1·12) |
| Obese | 1·91 (1·11, 3·27) | 1·60 (0·93, 2·76) | 1·01 (0·88, 1·16) | 1·05 (0·91, 1·21) | |
| 2004–2005 | Overweight | 1·43 (0·82, 2·48) | 1·12 (0·64, 1·97) | 1·07 (0·94, 1·21) | 1·09 (0·96, 1·25) |
| Obese | 1·65 (0·93, 2·93) | 1·43 (0·80, 2·56) | 1·30 (1·14, 1·49) | 1·33 (1·16, 1·52) | |
| 2009 H1N1 | Overweight | 1·81 (0·67, 4·91) | 1·54 (0·56, 4·27) | 0·98 (0·83, 1·16) | 1·14 (0·96, 1·35) |
| Obese | 2·26 (0·82, 6·23) | 1·90 (0·68, 5·27) | 1·09 (0·91, 1·29) | 1·23 (1·03, 1·47) | |
BMI, body mass index.
Severe ILI is a hospitalized ILI visit. Mild ILI is an outpatient ILI visit. Reference group is normal weight (BMI 18·5–24·9); overweight = BMI 25·0–29·9; obese = BMI ≥ 30. Adjusted for sex and age (continuous).