Predictors of influenza vaccine uptake: translation into Portuguese and validation of a questionnaire

Abstract: The difficulty in achieving ideal coverage rates with the influenza vaccine in Brazil and the growing wave of antivaccine movements in the world point to the need for a more in-depth understanding of the individual determinants of to this vaccine uptake. The Health Belief Model, a theoretical model that aims to explain and predict health-related behaviors, suggests that individual beliefs influence the adoption of health-related behaviors. The objective of this study was a cross-cultural adaptation of an instrument to assess predictors of influenza vaccine uptake in Brazilian adults. The authors conducted translation, back-translation, face validity, and a survey for construct validity. They also analyzed the factors associated with influenza vaccine uptake in 2017. An instrument originally with seven domains was identified and selected. In the factor analysis, four of the model’s seven constructs were validated: Susceptibility, Barriers, Cues to action, and Self-efficacy. In the survey with 396 persons, 59.3% reported having received the influenza vaccine in the last campaign in 2017. Female sex, age > 50 years, pregnancy, vaccination in private healthcare services, hepatitis B vaccination, and influenza vaccination prior to 2017 were associated with vaccination in 2017. In the final logistic regression model, perceived Barriers appeared as a strong factor for non-vaccination, while Cues to action increased the odds of vaccination.