Household Poverty and Movement Behaviors in Preschool Children: A Longitudinal Study of Physical Activity, Screen...

Background: Household poverty may shape physical activity (PA), screen time, and sleep during early childhood, but longitudinal evidence among preschool-aged children remains limited. This study examined longitudinal associations between household poverty status and these movement behaviors over 1 year. Methods: Data from 66 children aged 3-4.9 years were analyzed at baseline and 1-year follow-up. Parents reported sociodemographic characteristics and screen time, with poverty defined using household income and size. ActiGraph accelerometers (GT3X+) were worn for 7 days to estimate MVPA and nighttime sleep. Mixed-effects models examined associations between poverty status and each behavior, adjusting for child age, sex, race, and BMI percentile. Poverty status was assessed at each time point and treated as a time-varying exposure, and Time × Poverty interactions were included to test whether changes differed by poverty status. Results: At baseline, children living at/below the poverty level had higher screen time than children living above the poverty level (8.3 vs. 3.2 h/day, p < 0.05), and this descriptive difference remained at follow-up (7.0 vs. 3.1 h/day; p < 0.05). In adjusted linear mixed-effects models, children living at/below the poverty level had 2.8 additional hours/day of screen time at baseline (β = 2.84, 95% CI: 1.19-4.49, p = 0.001). The Time × Poverty interaction for screen time was not statistically significant (p = 0.64), suggesting no detectable difference in changes over time by poverty status. Poverty status was not significantly associated with MVPA or nighttime sleep, and their interactions with time were also not significant. Conclusion: Screen time was the only movement behavior independently associated with household poverty in this cohort. The non-significant findings for MVPA and nighttime sleep should be interpreted cautiously because of a small poverty subgroup and limited precision. Future studies should examine factors contributing to elevated screen use and evaluate strategies to reduce screen exposure among children from low-income households.