Table 2 Comparison of estimated risk of hospitalization associated with influenza season using different methods of defining the influenza season.
Flu Season Definition | Unadjusted Hazard Ratio (95% CI) | Adjusted Hazard Ratio* (95% CI) | Number of hospitalizations attributable to influenza | Rate of Attributable Excess hospitalizations** (95%CI) |
|---|---|---|---|---|
5% Moving Average | 1.09 (1.02–1.17) | 1.10 (1.04–1.18) | 109 | 12.72 (10.35 to 15.47) |
10% Moving Average | 1.04 (0.97–1.11) | 1.09 (1.02–1.17) | 74 | 8.64 (6.74 to 10.58) |
First/Last Isolate | 1.07 (0.995–1.14) | 1.08 (1.01–1.16) | 132 | 15.41 (12.54 to 18.74) |
5% Total Season Isolates | 1.07 (0.989–1.15) | 1.08 (1.00–1.17) | 51 | 5.95 (4.43 to 7.82) |