Study: Flu Vaccination in Hospitalized High-risk Patients "Paradoxically" Underutilized

August 21, 2020

Groups at high risk for influenza and its complications were less likely to receive vaccination while hospitalized vs the general population, according to a new study.

Groups at high risk for influenza and its complications were less likely to receive influenza vaccination while hospitalized than the general population.

The findings come from a retrospective cohort study that explored the utilization and impact of flu vaccination on cardiovascular outcomes in patients at high risk of complications; study results were presented during the Basic Cardiovascular Sciences Scientific Sessions virtual meeting by the American Heart Association, held virtually, July 27 to 30, 2020,.

Researchers from Texas Tech Univ Health Sciences Center, Paul L. Foster Sch of Med, El Paso, TX, used the 2014 National Inpatient Sample (NIS) database to identify individuals at high risk for influenza complications (n=7,056,314), as defined by the Center for Disease Control (CDC; ie, age ≥50; presence of chronic conditions; care in nursing facilities; presence of acquired immunodeficiency syndrome (AIDS); Native American or Alaskan Native descent; and high body mass index [BMI]).

Of the hospitalized patients at high-risk for influenza complications, 168,325 received an influenza vaccination. High-risk patients were less likely to be vaccinated during hospitalization (1.8%) compared with the general population (15.3%).

Patients aged ≥50 years at high risk for complications who received vs did not receive vaccination had a reduced risk for cardiovascular complications and hospital death: myocardial infarction (MI; predicted risk [PR], 0.72; P <.0001), death during hospitalization (PR, 0.27; P <.0001), transient ischemic attacks (TIA; PR, 0.53; P <.001), and cardiac arrest (PR, 0.15; P <.0001).

Vaccinated vs unvaccinated individuals at long-term care facilities had lower rates of MI (PR, 0.86; P =.003) and TIA (PR, 0.44; P <.0001). Vaccinated individuals of Native American or Alaska Native descent or those with a body mass index >30 kg/m2 had reduced instances of MI, death during hospitalization, and TIA compared with unvaccinated individuals of the same demography (P <.0001 for all).

Among patients with AIDS or who were immunocompromised, flu vaccination did not affect risk for MI (PR, 0.76; P =.591), death during hospitalization (PR, 0.22; P =.138), or TIA (PR, 0.77; P =.651).

“Flu vaccination was paradoxically underutilized in the high-risk patients and when used was associated with reduced rates of MI, TIA and cardiac arrest in all high-risk cohorts compared to those who did not receive vaccination,” the study authors wrote in conclusion. “These results underscore the need for health care policy initiatives to optimize flu vaccination among all patients and especially among high risk groups identified by the CDC.”

: Mandania R A, Ghosh A, Ma J, et al. Magnitude and impact of underutilization of flu vaccine in high-risk US cohorts on cardiovascular events. Presented at: American Heart Association: Basic Cardiovascular Sciences. 2020. Virtual meeting. July 27-30, 2020. Presentation #398.