Barriers to Flu Shot in ASCVD Patients: Age, Race, Healthcare Access

One-third of US adults with atherosclerotic cardiovascular disease (ASCVD) fail to get their annual flu shot, according to a new analysis. But some are at higher risk of skipping the vaccine than others—people at younger ages, those who identify as non-Hispanic Black, those without consistent access to healthcare or insurance, and those with less education or lower income.

Both the American Heart Association and the American College of Cardiology recommend influenza vaccination for secondary prevention in ASCVD patients (class I, level of evidence B), and the US Centers for Disease Control and Prevention (CDC) has advocated the same message for several decades. This is because influenza itself can spur acute CV events, and several studies have demonstrated vaccination can lower that risk.

Still, as has been shown before, a substantial segment of patients with heart disease continue to not get a flu vaccine.

The question, senior author Khurram Nasir, MD, MPH (Houston Methodist, TX), told TCTMD, is why there are such noticeable disparities. It may be thanks to choices made by individuals, and it may also be due to “social and health system barriers that didn’t allow them to get the much-needed care,” Nasir said. “One of the things that’s really disheartening is the significant social inequities among the most-vulnerable segments.” Many of the same sociodemographic groups who aren’t getting flu shots are those most at risk from the COVID-19 pandemic, he pointed out.

“We need to be mindful of these social determinants of health. We need to find strategies so that we engage these vulnerable populations and their communities,” Nasir advised. “And also in this journey we need to [make] concerted efforts in understanding how we can overcome these social barriers and provide them with the cheapest, most cost-effective healthcare that these patients deserve.”

Any and every effort that we make this season in improving flu vaccination is going to pay out huge dividends. Khurram Nasir

Influenza shares many symptoms with COVID-19, and it’s especially crucial to get ahead of things as this year’s flu season will put added burden on healthcare systems, Nasir stressed. “This is a sobering report, and I hope people will pay attention” to its implications, he said, calling for “collaborative action” at both the local and national levels so that these plans can be scaled up once a COVID-19 vaccine is available.

Millions of US Adults

For their study published online today in JAMA Cardiology, Gowtham R. Grandhi, MD, MPH (MedStar Union Memorial Hospital, Baltimore, MD), and colleagues analyzed Pooled Medical Expenditure Panel Survey data from 2008 to 2016 on adults 40 or older with ASCVD.

Their data set included 19,793 ASCVD patients, which would translate to 22.8 million US adults annually. Among them, 7,028 (32.7%) didn’t receive an influenza vaccine for that year’s season—corresponding to 7.4 million people on a national scale.

The strongest predictors of not being vaccinated were:

• Age 40 to 64 years (OR 2.32; 95% CI 2.06-2.62)
• Lack of usual source of care (OR 2.00; 95% CI 1.71-2.33)
• Absence of health insurance (OR 2.05; 95% CI 1.63-2.58)
• No education beyond high school (OR 1.25; 95% CI 1.12-1.40)
• Family income < 200% federal poverty level (OR 1.14; 95% CI 1.01-1.27)
• Non-Hispanic Black ethnicity/race (OR 1.24; 95% CI 1.10-1.41)

There was a stepwise increase in risk for no vaccination as patients accumulated more high-risk characteristics. Among those with four or more of these factors, 59.7% said they didn’t get a flu shot—amounting to 732,524 US adults annually (OR 6.06; 95% CI 4.88-7.53).

Every Bit Helps

“Disparities in access and influenza vaccine use have been previously described,” Laurence S. Sperling, MD (Emory University, Atlanta, GA), Michelle A. Albert, MD, MPH (University of California, San Francisco), and Ram Koppaka, MD, PhD (CDC, Atlanta, GA), observe in an editorial. “However, to our knowledge, the report by Grandhi et al is the first to highlight the potential magnitude of this gap associated with sociodemographic and age-related disparities specifically among people living with ASCVD, possibly affecting millions of individuals in the US.”

Expanded insurance coverage could be a solution but is just one of many factors, they say. “Barriers likely may exist at the patient, clinician, community, and healthcare system levels. Given the number of individuals living with ASCVD in the US, multifaceted approaches will likely be required to reduce the identified disparities.”

In terms of public health, Nasir said, research needs to be done to pinpoint why there are disparities and to guide strategies for overcoming them. Pharmacies are popular places to get vaccinated, but a more-creative approach—a barbershop intervention, for example, had lasting effects on blood pressure—may have greater sway in some communities. Practices, too, can choose a “champion” to identify patients who merit outreach, he suggested.

A key message to cardiologists is that the flu vaccine is a simple, inexpensive way to reduce cardiovascular events, said Nasir. “Have a discussion with your patient. Make sure [for] every patient with CVD that every opportunity you have, whether you’re seeing them in the hospital or as an outpatient, [you encourage them to] get their influenza vaccine.”

If time is a barrier during appointments, vaccine-promoting materials from the CDC can be placed in the waiting room, he added. “Any and every effort that we make this season in improving flu vaccination is going to pay out huge dividends.”