Screen exposure patterns and their associations with obesity and sleep among preschool children in a resource-limited city in eastern China: a multicenter cross-sectional study protocol.

INTRODUCTION: Electronic screen exposure is increasingly common among preschool children and has been associated with sleep-related outcomes and overweight/obesity. However, evidence from resource-limited areas in eastern China remains limited, particularly regarding multidimensional screen-use patterns. This study aims to describe the prevalence and patterns of screen exposure among preschool children, primarily to examine the association between excessive screen exposure and overweight/obesity, and secondarily to examine associations with sleep-related indicators.

METHODS: This kindergarten-based, multicenter analytical cross-sectional study will be conducted in Suqian, a resource-limited city in eastern China. Preschool children aged 3-6 years and their primary caregivers will be recruited using stratified multistage random sampling. Information on screen exposure, child and family characteristics, family media environment, and sleep-related indicators will be collected using a structured questionnaire completed by the child's primary caregiver. Children's height and weight will be measured by trained kindergarten staff using standardized procedures. Excessive screen exposure will be defined as average daily screen time >1 h/day, with ≤1 h/day used as the reference category. Overweight/obesity will be the primary outcome. Survey-weighted Poisson regression with a log link and robust variance estimation will be used to estimate prevalence ratios and 95% confidence intervals for the primary association, accounting for the stratified multistage cluster sampling design and survey weights. Associations between screen exposure and individual sleep-related indicators will be examined separately as secondary analyses using survey-weighted ordinal logistic regression models.

DISCUSSION: This study will provide context-specific epidemiological evidence on screen exposure patterns among preschool children in a resource-limited setting in eastern China. By examining multidimensional screen-use behaviors and their association with overweight/obesity, while also assessing sleep-related indicators as secondary outcomes, the study may inform future health promotion strategies and provide a basis for longitudinal research on screen exposure and child health.

CLINICAL TRIAL REGISTRATION: https://www.chictr.org.cn; identifier ChiCTR2600126288.