Validation of the behavioural and social drivers of influenza vaccine survey in Australia: Cognitive interviews and psychometric evaluation.

Seasonal influenza vaccination reduces the risk of contracting influenza. In Australia, vaccination coverage is consistently low among the most at-risk groups eligible for the free influenza vaccine. To establish an annual national monitoring of the behavioral and social drivers of influenza vaccination, we validated the World Health Organization's Behavioral and Social Drivers of Influenza Vaccination survey. Ours is the first study reporting the validation results of the newly developed survey tool. Two validation stages occurred: first, cognitive interviews and survey item revisions based on feedback; second, collecting quantitative data, performing psychometric analysis, including factor analysis, and assessing the association between survey items and influenza vaccination intention using polychoric correlation and a random forest model to determine each item's importance. We modified nine of the 31 survey items based on cognitive interviews with 16 adults. Based on the psychometric evaluation of 2055 respondents, we identified and validated five factors that underlie the survey structure and aligned well with the four domains of the BeSD framework: Thinking and Feeling, Social Processes, Motivation, and Practical Issues. Each item correlated with the intention to receive influenza vaccine, particularly those related to perceived vaccine importance and social responsibility. We recommend further validation in various contexts, especially to assess the survey's predictive validity regarding actual vaccination uptake.