Influenza Vaccine Uptake and Missed Opportunities Among the Medicare-Covered Population With High-Risk Conditions During the 2018 to 2019 Influenza Season A Retrospective Cohort Study

Background: Seasonal influenza causes substantial morbidity and mortality among older U.S. adults and those with comorbid health conditions. Objective: To describe seasonal influenza vaccine uptake and identify factors associated with missed opportunities for influenza vaccination. Design: Retrospective cohort study. Setting: Medicare fee-for-service claims. Participants: 31.6 million U.S. adults continuously enrolled under Medicare Parts A and B during the 2018 to 2019 influenza season. Measurements: Influenza vaccine uptake and missed opportunities by patient demographic characteristics, high-risk status (that is, >= 1 condition increasing influenza complication risk), MedicareMedicaid dual-eligibility status, and health care provider visits (that is, vaccination opportunities). Results: Overall, 50.5% of beneficiaries aged 19 years or older had Medicare claims for influenza vaccination: 31.6% among people aged 19 to 64 years and 54% among people aged 65 years or older. More White beneficiaries were vaccinated (52.9%) than Black (34.9%) or Hispanic (30.4%) beneficiaries. Uptake was higher (56.1%) for beneficiaries with high- risk conditions than for those without (27.6%). Among unvaccinated beneficiaries overall, 77.4% visited a provider during influenza season; among unvaccinated beneficiaries with and without high-risk conditions, 91% and 43%, respectively, had seen a provider at least once. The proportion of beneficiaries with missed opportunities for influenza vaccination was 44.2% and was higher for beneficiaries in the non-high-risk group (59.1%) than those in the high-risk group (42.2%). Uptake was lower and proportions of missed opportunities were higher among beneficiaries in younger age groups, of Black and Hispanic race/ethnicity, without high-risk conditions, or with Medicare-Medicaid dual eligibility. Limitations: Influenza vaccinations without claims could not be captured. Data on reasons for nonvaccination were unavailable. Conclusion: Influenza vaccination coverage for Medicare beneficiaries continues to be suboptimal, with missed opportunities despite availability of influenza vaccination with no copayment. Disparities persist in vaccination uptake by race/ethnicity.