Disparities in Influenza Vaccination Among Adults With Cardiovascular Disease

A large portion of adults with established atherosclerotic cardiovascular disease (ASCVD) in the United States lack influenza vaccine. Furthermore, several sociodemographic subgroups are at greater risk, according to data published in JAMA Cardiology. 

Influenza vaccination among adults with ASCVD has been shown to decrease overall morbidity, mortality, severity of infection, and hospital readmission. Information regarding vaccination rates in this group are limited. Investigators used Pooled Medical Expenditure Panel Survey data from 2008 to 2016 and included adults 40 years or older with ASCVD to evaluate prevalence of and sociodemographic disparities in influenza vaccination among individuals with ASCVD.

Out of 131,881 individuals, 19,793 (15.7%) had ASCVD, ascertained via self-report and/or International Classification of Diseases, Ninth Revision diagnosis of coronary heart disease, peripheral artery disease, and/or cerebrovascular disease. This corresponds to 22.8 million US adults annually. Within the sample of ASCVD cases, 7028 (32.7%) adults lacked vaccination, corresponding to 7.4 million adults nationally. High-risk groups with higher odds for lacking vaccination were found among individuals aged 40 to 64 years (OR, 2.32; 95% CI, 2.06-2.62), without a usual source of care (OR, 2.00; 95% CI, 1.71-2.33), without insurance (OR, 2.05; 95% CI, 1.63-2.58), with a lower education level (OR, 1. 25; 95% CI, 1.12-1.40), with a lower income level (OR, 1.14; 95% CI, 1.01-1.27), and of non-Hispanic or Black race/ethnicity (OR, 1.24, 95% CI, 1.10-1.41).

Investigators further report a stepwise increase in the prevalence and odds of lacking influenza vaccination among individuals with increases in high-risk characteristics. In total, 1171 individuals (59.7%; 95% CI, 55.8%-63.5%) with 4 or more high-risk characteristics and ASCVD, corresponding to 732,524 US adults annually, reporting lacking influenza vaccination; this group has 6-fold higher odds (OR, 6.06; 95% CI, 4.88-7.53) of lacking vaccination compared to individuals without any high-risk characteristics.

The cross-sectional nature of the data set limits the ability to assess causal relationships between demographics and vaccination within the past year. Researchers acknowledge the possibility of “a bilateral relationship in which individuals’ socioeconomic and environmental circumstances may inhibit access to health care services such as vaccination and that resulting poor health can influence future financial status cannot be discounted.” The presence or absence of vaccination has highly confounded the observational analyses associating flu vaccines with lower incidence of cardiovascular events. This led to the recommendation that well-powered randomized clinical trials, such as the upcoming INVESTED trial (NCT02787044), are absolutely necessary to evaluate the protective effects of vaccination on cardiovascular events.

Nearly one-third of US adults with ASCVD are lacking influenza vaccination, and disproportionally higher rates are observed among vulnerable sociodemographic groups. Investigators highlight that these findings “underscore the importance of focused public health interventions and awareness efforts aimed at increasing access to and use of influenza vaccinations among these higher-risk subgroups with underlying cardiovascular conditions.”

Disclosure: Several authors declared affiliations with various industries. Please see the original reference for a full list of authors’ disclosures.

Reference

Grandhi GR, Mszar R, Vahidy F, et al. Sociodemographic disparities in influenza vaccination among adults with atherosclerotic cardiovascular disease in the United States. Published online September 9, 2020. JAMA Cardiol. doi:10.1001/jamacardio.2020.3978