Preschool Child Development

Neurodevelopmental disorders (NDDs) in preschoolers are frequently accompanied by persistent sleep disturbances, such as delayed sleep onset and reduced sleep duration, which exacerbate behavioral problems, impair cognitive development, and increase parental stress. While behavioral parent education effectively improves sleep hygiene, access to in-person clinical programs remains limited by high parent dropout rates. Digital delivery offers a flexible, scalable alternative, yet randomized controlled trials (RCTs) evaluating both face-to-face and self-help mobile app formats specifically for preschoolers across NDDs remain scarce. This study is a three-arm RCT designed to evaluate and compare the efficacy of a parent-based sleep intervention delivered via face-to-face group sessions combined with usual care (UC) versus a digital self-help mobile application combined with UC, against UC alone in Hong Kong preschoolers with NDDs. The study also assesses downstream effects on child daytime behaviors, parental stress, and parent sleep/mood outcomes over a 12-month period.