Compositional time-use and psychosocial health in young children: a longitudinal study

Abstract BackgroundGood quality sleep, regular physical activity, and limited time spent sedentary are all considered individually important in promoting good mental health in children. However, few studies have examined the influence of each behaviour simultaneously, using compositional analysis which accounts for the closed nature of the 24-hour day. Our aim was to determine how compositional time use in early childhood is related to mental and psychosocial health at five years of age.Methods392 children wore Actical accelerometers 24-hours a day for one week at 2, 3.5 and 5 years of age to examine time in sleep, physical activity, and sedentary behaviour. Psychosocial and mental health were assessed at age 5 using both laboratory based (researcher-assessed) and questionnaire (parental-report) measures. Associations were estimated using regression models with isometric log-ratios of time-use components as predictors.ResultsCross-sectionally, 5-year old children who spent 10% (64 minutes) more time asleep than average had better inhibitory control (standardised mean difference; 95% CI: 0.19; 0.02, 0.36 for Statue test and 0.16; -0.01, 0.33 for Heads, Toes, Knees, Shoulders task). A greater proportion of time spent active (10%, 31 minutes) was associated with poorer inhibitory control (Statue: -0.07; -0.13, -0.02, Head, Toes, Knees, Shoulders task: -0.06; -0.11, -0.01). By contrast, differences in time-use were not meaningfully associated with any measure of self-regulation or mental health at 5 years of age, nor were any significant longitudinal relationships apparent.Conclusions24-hour time use in the preschool years was not significantly associated with any measure of psychosocial or mental health at 5 years of age, although some relationships with inhibitory control were observed cross-sectionally.Trial registration: ClinicalTrials.gov number NCT00892983