Objectives: There is limited evidence on the effectiveness of influenza vaccination on hospitalization outcomes by cardiovascular disease (CVD) subtypes or comorbidities.
Methods: This study involved 713,488 records of hospitalization of adults ≥60 years with CVD from the Beijing Urban Employee Basic Medical Insurance database. Logistic regression with generalized estimating equations was conducted to estimate the effectiveness of influenza vaccination on in-hospital death and recurrent hospitalization, adjusting for unmeasured confounders.
Results: The coverage of influenza vaccination was only 13.3% among older adults hospitalized for CVD. Influenza vaccination was associated with 15% (odds ratios 0.85 [0.74, 0.99]) lower risk of in-hospital death among patients with CVD, with stronger associations in patients with stroke. Influenza vaccination was associated with 6% (0.94 [0.88, 0.99]) and 28% (0.72 [0.56, 0.93]) lower risks of recurrent hospitalization for ischemic heart disease (IHD) and respiratory disease in patients with IHD, but there were no clear associations in patients with stroke. For in-hospital death, the protective association of influenza vaccination was stronger in patients with fewer comorbidities and was similar to that of joint vaccinations of influenza and pneumococcal vaccinations.
Conclusion: The protective association of influenza vaccination on CVD hospitalization outcomes serves as the evidence base to increase the uptake of influenza vaccination among older adults in China.
Keywords: Cardiovascular diseases; In-hospital death; Influenza vaccination; Older adults; Recurrent hospitalization.
Copyright © 2022. Published by Elsevier Ltd.