Many US Adults with Atherosclerotic Cardiovascular Disease Lack Flu Shots

Large groups of individuals with atherosclerotic cardiovascular disease (ASCVD) lack influenza vaccinations, new research suggests.

A new study in JAMA Cardiology looked at various sociodemographic subgroups to determine disparities in those who had the vaccine for seasonal influenza and those who did not. The authors noted that ASCVD is a leading cause of death and disability around the world, and also that the influenza vaccine itself has been associated with reduced morbidity, mortality, infection severity, and hospitalizations.

“National estimates of influenza vaccination among individuals with ASCVD in the US are not well studied,” the authors wrote, stating their objective as evaluating “the prevalence of and sociodemographic disparities in influenza vaccination among a nationally representative sample of individuals with ASCVD.”

The study consisted of data on individuals 40 years and older  from the Pooled Medical Expenditure Panel Survey data from 2008 to 2016. The primary outcomes of interest were the prevalence and characteristics of adults with ASCVD who didn’t have a flu shot during the past year. The team looked at covariates like age, sex, race/ethnicity, family income, insurance status, education, and care source.

According to the results, of the 131,881 adults in the study sample, 19,793 (15.7%) had ASCVD, which corresponded to approximately 22.8 million US adults per year. More than 7,000 adults with ASCVD (n=7,028; 32.7%) lacked a flu shot within the past year. Upon analysis, characteristics of those with the highest odds of lacking a vaccination were age 40-64 (OR=2.32; 95% CI, 2.06 to 2.62), those with no source of care (OR=2.00; 95% CI, 1.71 to 2.33), those without insurance (OR=2.05; 95% CI, 1.63 to 2.58), those with a low level of education (OR=1.25; 95% CI, 1.12 to 1.40), those at a low income level (OR=1.14; 95% CI, 1.01 to 1.27), and those of non-Hispanic black race/ethnicity (OR=1.24; 95% CI, 1.10 to 1.41). There was also a stepwise increase in the prevalence of the odds of lacking a flu shot in those at high risk (n=1,711): those individuals with four or more high-risk characteristics and ASCVD (a little more than 732,000 US adults annually) reported a lack of influenza vaccination (OR=.606; 95% CI, 4.88 to 7.53).

“Despite current recommendations, a large proportion of US adults with established ASCVD lack influenza vaccination, with several sociodemographic subgroups having greater risk,” the authors concluded. “Focused public health initiatives are needed to increase access to influenza vaccinations for high-risk and underserved populations.”