Latent Trajectories of Screen Time and Their Predictors in School-Aged Children: A Six-Year Longitudinal Analysis.

OBJECTIVE: Children's screen time has increased rapidly with the rise of digital technology and was further accelerated by the COVID-19 pandemic, heightening concerns about developmental impacts. This study investigates six-year trajectories of children's screen time, identifies usage profiles, and examines key social and behavioral factors influencing these patterns during and after the pandemic. METHODS: We analyzed data from 313 children participating in a prospective South Korean cohort study (2018-2023). Caregivers reported weekday and weekend screen time on smartphones, tablets, and personal computers (PCs). Joint latent class profile analysis (JLCPA) identified trajectories, and multinomial logistic regression tested the influence of child sex, age, parental education, household income, and Child Behavior Checklist (CBCL) scores. RESULTS: Screen time increased across devices, particularly smartphones and PCs. JLCPA revealed four distinct trajectories: low-risk (27.2%), mid-risk (38.4%), risk-increasing (15.3%), and high-risk (19.1%). Membership in the high-risk trajectory increased during and after the COVID-19 pandemic. Significant differences were observed across trajectories, with lower maternal education and male sex emerging as the most robust predictors of higher-risk membership. Children whose mothers had lower educational attainment were up to six times more likely to belong to the high-risk trajectory. Older age and higher caregiver-reported CBCL scores were also associated with increased odds of membership in higher-risk trajectories. CONCLUSION: Children's screen time behaviors are diverse and shaped by developmental, familial, and socioeconomic factors, with notable pandemic-related changes. Tailored interventions and continued research are essential to promote healthy digital habits and mitigate potential risks.