Rationale and Design of a Multi-National Study of Physicians' Opinions, Attitudes, and Practices Regarding Influenza Vaccination in Patients with Cardiovascular Diseases: A Mixed Methods Designs. The FLUence Project

Infections, particularly those involving the respiratory tract, are associated with an increased incidence of cardiovascular events, both de novo and as exacerbations of pre-existing cardiovascular diseases. Influenza vaccination has consistently been shown to reduce the incidence of cardiovascular events. Nonetheless, vaccination rates among adults remain suboptimal, both in the general population and among high-risk individuals. Multiple barriers hinder achieving adequate vaccination rates, with physicians' beliefs and attitudes towards these interventions being crucial. The FLUence project was developed within the framework of the World Heart Federation's Emerging Leaders program, to address this issue. This project has two phases: a global quantitative survey to assess the perceptions, opinions, and attitudes and challenges of physicians worldwide regarding the safety and efficacy of the influenza vaccination use, and a qualitative survey to further investigate the barriers and facilitators of recommending and using this vaccination. The quantitative survey was created and disseminated in five languages (English, Spanish, French, Italian, and Portuguese) to physicians of all specialties who care for adults, with a particular focus on patients with cardiovascular disease. The survey included eight domains with a total of 36 questions with closed options; a Likert scale with five possible answers was used to gauge participants' opinions. To gain deeper insights into the complexities behind the low vaccination rates in adults, the second part of the project comprises a qualitative survey, conducted in the two lower-middle- and upper-middle-income countries: India and Argentina, respectively. These countries were selected because patients with cardiovascular diseases have access to free influenza vaccination in Argentina, whereas patients must pay for the vaccine out of pocket in India. Thus, the FLUence study will provide valuable information to better understand the perceptions and barriers to improving influenza vaccination rates from the perspective of physicians. It is imperative to actively engage all healthcare providers to improve influenza vaccination rates.