Table 3.
Crude and adjusted odds ratio (OR) and 95% confidence intervals (95% CI) for severe and mild influenza-like illness (ILI) by season
| Influenza season | BMI category | Severe ILI | Mild ILI | ||
|---|---|---|---|---|---|
| Crude OR | Adjusted OR | Crude OR | Adjusted OR | ||
| 2003–2004 | Overweight | 1·16 (0·82, 1·64) | 0·88 (0·61, 1·26) | 0·96 (0·86, 1·08) | 0·99 (0·89, 1·12) |
| Obese | 1·46 (1·03, 2·07) | 1·14 (0·80, 1·64) | 1·08 (0·96, 1·21) | 1·06 (0·94, 1·19) | |
| 2004–2005 | Overweight | 1·40 (0·98, 1·99) | 1·11 (0·77, 1·59) | 1·07 (0·96, 1·19) | 1·06 (0·95, 1·18) |
| Obese | 1·62 (1·14, 2·31) | 1·24 (0·86, 1·79) | 1·33 (1·20, 1·48) | 1·26 (1·13, 1·40) | |
| 2009 H1N1 | Overweight | 1·44 (0·71, 2·90) | 1·09 (0·53, 2·24) | 1·03 (0·89, 1·19) | 1·17 (1·00, 1·35) |
| Obese | 2·71 (1·42, 5·17) | 1·76 (0·91, 3·42) | 1·16 (1·00, 1·34) | 1·22 (1·05, 1·42) | |
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). Adjusted for sex, age (continuous), and Charlson Comorbidity Index score (continuous).