Who would take part in a pandemic preparedness cohort study? The role of vaccine-related affective polarisation: cross-sectional survey

IntroductionCohort studies are an important tool for public health research about emerging infectious diseases. The COVID-19 pandemic resulted in polarised opinions about important preventive measures, such as vaccination. Affective polarisation, an affinity for people with similar attitudes to oneself and hostility toward those with opposing views, is a measure of peoples feelings about these issues. The aim of this multidisciplinary study was to investigate factors associated with willingness to participate in a future household-based cohort study on pandemic preparedness. MethodsWe did a cross-sectional online survey in the Canton of Bern, Switzerland. We invited a random sample of persons aged 18+ years from 15,000 private households. We asked about willingness to take part in a future cohort study and collected data about demographic, social and household characteristics, and affective polarisation related to COVID-19 vaccination. We performed univariable and multivariable analyses, weighted by household size to estimate odds ratios (with 95% confidence intervals, CI). ResultsThe survey response rate was 22.6% (n=3,394). Among responders, 49.8% (95% CI 47.9-51.8, weighted proportion) were willing to take part in a cohort study. In multivariable analysis, higher educational level (adjusted odds ratio 2.48, 95% CI 1.81-3.39) and higher monthly income (1.92, 1.39-2.65) were most strongly associated with higher willingness to participate. Opposition to COVID-19 vaccination was associated with lower willingness to participate (0.53, 0.39-0.72). Affective polarisation modified the relationship between vaccination attitudes and willingness to participate. Compared with non-polarised vaccination supporters, polarised supporters were more willing to participate (marginal adjusted odds ratio 1.51, 1.05-2.16), whereas willingness to participate was lower among both non-polarised (0.53, 0.32-0.86) and affectively polarised (0.26, 0.12-0.56) vaccination opposers. ConclusionsWillingness to participate in a cohort study was low. Following the COVID-19 pandemic, addressing affective polarisation, as well as socioeconomic factors, is needed to improve participation in pandemic preparedness research. KEY MESSAGES WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?In public health research, willingness to participate in long-term cohort studies is associated with sociodemographic factors such younger age and higher levels of education and income. WHAT THIS STUDY ADDS?In an online cross-sectional survey of randomly selected households, about half of respondents were willing to take part in a future cohort study. In addition to the known sociodemographic factors, negative opinions about COVID-19 vaccination were associated with lower willingness to participate and affective polarisation, expressed as emotional affinity towards individuals with similar opinions and hostility to those with other opinions, were also associated with higher willingness to participate. HOW MIGHT THIS STUDY AFFECT RESEARCH, PRACTICE OR POLICY?Willingness to participate in a long-term cohort study about pandemic preparedness was low. Following the COVID-19 pandemic, a multidisciplinary approach addressing affective polarisation, as well as socioeconomic factors, is needed to improve participation in pandemic preparedness research.