Correlates of physical activity behaviour in a population sample with increased cardiovascular risk and established cardiovascular disease: Cross-sectional analysis of data from the Paracelsus 10,000 prospective cohort study in Salzburg, Austria.

Regular physical activity (PA) remains challenging for many people with high cardiovascular risk and established cardiovascular disease (CVD). We aimed to study correlates of PA behaviour in a population sample with increased cardiovascular risk and established CVD in Austria. We analysed cross-sectional data from the Paracelsus 10,000 study, a population-based cohort study of 40-70-year-olds in the city of Salzburg, Austria, and its surroundings. In a sub-sample of participants with increased cardiovascular risk and established CVD, we examined the associations between 29 correlates and leisure-time PA (weekly hours of walking, cycling and doing sports) as the primary PA outcome, as well as four secondary PA outcomes. We used stepwise multiple regression and machine learning models (decision trees, support vector machines, k-nearest neighbours, random forest and gradient boosting) to examine these associations. We analysed data from 1,173 participants with mean age 60.5 years (range 42-72 years). Nineteen percent of participants were female. Across the different PA outcomes and statistical analysis models, retirement, more PA during earlier life decades, and adherence to a Mediterranean diet were positively associated with PA behaviour. Greater comorbidity and depression were inversely associated with PA. In stepwise multiple regression, adjusted effect estimates on the primary PA outcome were 1.5 (SE 0.7, p = 0.0310) for retirement, 4.1 (SE 3.1, p < 0.0001) for past PA behaviour, 0.5 (SE 0.2, p = 0.0027) for Mediterranean diet, and -0.2 (SE 0.1, p = 0.0180) for depression. These findings contribute to a better understanding of the correlates of PA behaviour in populations at increased cardiovascular risk and with established CVD and may inform approaches for selective and personalised PA promotion strategies in cardiovascular care.