Influenza vaccine effectiveness against hospitalization and all-cause mortality during influenza periods, 2000–01 to 2005–06 with and without adjustment for multiple and select covariates.

Note. IVE = influenza vaccine effectiveness; CI = confidence interval; Hosp = hospitalization with pneumonia, influenza, or acute respiratory disease listed as most responsible admission diagnosis; Death = all-cause mortality; SES = socioeconomic status.aAdjusted for all following covariates: age, sex, socio-economic status, urban residency, prior influenza immunization (two year), prior pneumococcal immunization, medical visits prior year, and Elixhauser index.bAdjusted for select influential covariates of age, prior influenza (two year) and pneumococcal immunization and medical visits prior year.cMatched on propensity scores, calculated based on age, sex, socio-economic status, urban residency, prior influenza immunization (two year), prior pneumococcal immunization, medical visits prior year, and Elixhauser index.dSelect adjustment includes pneumococcal immunization, medical visits prior year, and age.eData aggregated across all six seasons for hospitalization and across all seasons except 2003–04 for mortality.