RESUMO
OBJECTIVES: To explore associations of screen time (total, mobile gaming) with sleep problems in Chinese young adults. METHODS: This was a 4-week daily morning (completion rate = 82.1%, 909/1107) and evening (completion rate = 92.4%, 1061/1148) assessment study in 41 university students (22 female, mean age = 22.3 [SD 4.2] years). Short sleep duration < 7 h, difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, and any of these three insomnia symptoms were self-reported in the morning. Mobile gaming time was self-reported in the evening, whilst total screen time was objectively tracked. Bayesian multilevel mixed-effects modeling disaggregated between- and within-person associations. RESULTS: Between person, longer mobile gaming time predicted short sleep duration (adjusted odds ratio [AOR] = 1.90, 95% CI 1.39, 2.69), any insomnia symptoms (AOR = 1.59, 95% CI 1.20, 2.11), difficulty initiating sleep (AOR = 3.05, 95% CI 1.51, 6.24), and difficulty maintaining sleep (AOR = 2.19, 95% CI 1.18, 3.74). Short sleep duration (adjusted b = 0.99, 95% CI 0.05, 1.95), any insomnia symptoms (adjusted b = 1.19, 95% CI 0.24, 1.94), and difficulty initiating sleep (adjusted b = 1.72, 95% CI 0.11, 3.19) reversely increased mobile gaming time. Within person, any insomnia symptoms (adjusted b = 0.17, 95% CI 0.04, 0.31) and early morning awakening (adjusted b = 0.28, 95% CI 0.08, 0.48) increased next-day mobile gaming time. Total screen time was not associated with sleep problems both between and within person. CONCLUSIONS: Bidirectional between-person associations of mobile gaming time with short sleep duration and insomnia symptoms informed multiple-health-behavior-change interventions. Unidirectional within-person associations of insomnia symptoms with next-day mobile gaming time informed just-in-time adaptive interventions addressing daily variations in insomnia symptoms. [250/250 word limits].