Understanding variations in the built environment over time to inform longitudinal studies of young children's...

We know relatively little about the role the neighbourhood built environment plays in promoting young children's physical activity, particularly its longitudinal effect either through repeated exposure to the same environment or through change in exposure by moving from one neighbourhood to another. This study characterised the neighbourhood environment of young children in the PLAYCE cohort study over three timepoints from 2015 to 2023. There were statistically significant differences in built environment attributes between timepoints and across socio-economic status, however they did not represent practically significant differences. These findings inform the analysis approach of subsequent research in the BEACHES Project, an international study examining the role of the built environment on child physical activity and obesity using multiple cohorts.