Effects of annual influenza vaccination on mortality in patients with heart failure.

ABSTRACT

The objective was to evaluate the effect of influenza vaccine on all-cause mortality in a cohort of patients with heart failure followed up in primary care centres of the Community of Madrid, Spain, during the period 2006-10. Results of the Cox proportional-hazard model were adjusted for age and sex and, after 11 nearest neighbour matching, for propensity score. The analysis was further stratified by season. Having received annual influenza vaccine was associated with a decreased risk of death during the influenza season (hazard ratio = 0.59, 95% CI = 0.41-0.84), but no protective effect was observed before or after the influenza season.