Association between changes in parents' and children's adherence with the 24 h movement behaviour guidelines during the COVID-19 pandemic: a national longitudinal study.

Many cross-sectional studies have examined associations between parents' and children's movement behaviours, focusing on single behaviours, despite these behaviours being interdependent. This longitudinal study examined associations between parents' and children's adherence to the Canadian 24 h movement guidelines. An online national survey was conducted with parents of 7-12-year-olds (N = 2257; 51.6% boys) in December 2020, and every 6 months until June 2022 (four waves). Multinomial regression models embedded in generalized estimating equations were used to model associations between changes in parents' adherence to the guidelines, perceived behavioural control (PBC) to support their child's movement behaviours, and changes in children's adherence to the guidelines at each wave. The final model was adjusted for age, child and parent gender, household income, immigration status, and study wave. Across all waves, over two-thirds of parents and children did not meet the guidelines. Accordingly, maintaining nonadherence was used as the reference group. Children whose parents maintained adherence were more likely to maintain adherence (odds ratio (OR) = 3.25, 95% confidence interval (CI): 1.80-5.85) and to change from adherence to nonadherence (OR = 2.21, 95% CI: 1.32-3.71). Children whose parents shifted from nonadherence to adherence were more likely to maintain adherence (OR = 1.82, 95% CI: 1.15-2.88), shift from adherence to nonadherence (OR = 1.91, 95% CI: 1.25-2.92), and from nonadherence to adherence (OR = 2.05, 95% CI: 1.41-2.96). Each unit increase in parental PBC was associated with higher odds of children maintaining adherence (OR = 3.80, 95% CI: 2.27-6.36). These findings support the importance of parental role-modelling and PBC to support their child's movement behaviours, suggesting a need for family-based interventions.