Abstract
BACKGROUND: Influenza vaccination and lipid lowering therapy (LLT) are evidence-based interventions with substantial benefit for individuals with established atherosclerotic cardiovascular disease (ASCVD). However, levels of influenza immunization and LLT use are low, possibly due to pervasive fear-based misinformation uniquely targeting vaccines and LLT. Whether being unvaccinated for influenza predicts lower utilization of LLT is unknown. OBJECTIVES: We tested the hypothesis that American adults with ASCVD who are unvaccinated for influenza have lower use of LLT even after accounting for traditional factors associated with underuse of preventive therapies. METHODS: We pooled 2017, 2019, and 2021 survey data from the Behavioral Risk Factor Surveillance System (BRFSS), and selected respondents aged 40 to 75 years with self-reported ASCVD. We used logistic regression models adjusted for potential confounders to examine the association between influenza vaccination and self-reported LLT use. We performed a sensitivity analysis with multiple imputation to account for missing data. All analyses accounted for complex survey weighting. RESULTS: Of 66,923 participants with ASCVD, 55% reported influenza vaccination in the last year and 76% reported using LLT. Being unvaccinated for influenza was associated with lower odds of LLT use (OR 0.54; 95% CI 0.50, 0.58; P< .001). In a multivariable regression model adjusting for demographics and comorbidities, this association remained statistically significant (aOR 0.58, 95% CI 0.52, 0.64, P < .001). After additional adjustment for preventive care engagement, health care access, and use patterns of other cardiovascular medications this association persisted (aOR 0.66; 95% CI 0.60, 0.74; P < .001). There were no significant differences across subgroups, including those with and without hyperlipidemia. CONCLUSIONS: Unvaccinated status for influenza was independently associated with 34% lower odds of LLT use among American adults with ASCVD after adjustment for traditional factors linked to underuse of preventive therapies. This finding identifies a population with excess modifiable ASCVD risk, and supports investigation into nontraditional mechanisms driving underuse of preventive therapies, including fear-based misinformation.