Influencing factors of physical activity in youths with cystic fibrosis: a socioecological approach.

Background: Physical activity (PA) is a multidimensional behaviour influenced by various factors and is lower in youth with cystic fibrosis (YwCF). While regular PA is known to have a positive effect on health, research on its influencing factors is limited and inconsistent. Therefore, we aimed to explore the influencing factors of YwCF by applying the socioecological model (SEM), a comprehensive framework accounting for these influences. Methods: YwCF between 6 and 17 years were recruited. PA was measured over 7 consecutive days with an ActiGraph GT3X-BT, and total PA and time in at least moderate-to-vigorous intensity PA (MVPA) were chosen as primary outcomes. Regression analyses were executed to test the association between influencing factors across the different levels of the SEM ( Results: This cross-sectional study included 49 YwCF (57% female; 11.3±3.3 years). For total PA, significant bivariable associations were found on all levels of the SEM: intrapersonal (age, waist circumference, functional performance, quality of life, attitudes towards PA, screen time), interpersonal (social support), organisational (participation in organised sports) and community (season). Based on the multivariable models, the sociodemographic factor age accounts for the highest variance in total PA (adjR Conclusion: Our findings underscore the multifaceted nature of PA behaviour in YwCF and highlight the need for future PA interventions to recognise these multiple levels of influence.