A review of developmental consequences of poor sleep in childhood.

Sleep is a fairly diverse and complex construct to operationalize in a scientific and naturalistic context. We report a systematic review and meta-analysis of reviews published in the last 5 years on poor sleep and developmental outcomes. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, 42 articles (or 1117 studies) qualified. They reported outcomes related to poor sleep investigated as sleep disorders (38.1%), sleep 'in general' (26.2%), sleep duration (23.8%), in terms of circadian rhythm (4.8%), intra-individual variability (2.4%), and napping (2.4%). Sleep was primarily subjectively reported (30.2%), yet the methodology of sleep assessment was often neither tabulated nor discussed. Overall, most papers had a health-scope, being primarily weight problems expressed as body mass index. Its relationship with performance was measured with the Wechsler intelligence tests, the child behavior checklist and the continuous performance test, whereas meta-analytic papers specifically focused on cognition with sleep disorder (i.e. sleep-disordered breathing; 38.6%), on health (i.e. weight) with sleep duration (25%) and behavior with sleep 'in general' (15.9%), having a high true variance. Nevertheless, an aggregated effect size d of 0.35 (95% confidence interval: 0.27-0.42) suggests that poor sleep is moderately affecting a child's performance and health. In conclusion, poor sleep can no longer be disregarded, yet methodologies that are more rigorous and a scope beyond health may foster a better understanding of the role of (poor) sleep across childhood neurodevelopment.