Impact of a mobile health intervention on health management among children with phenylketonuria based on a multi-theory model of the behavior change wheel theory and family health theory: protocol for a randomized controlled trial

Jie Wang¹Yang Sihan²Jing Wang²Bo Zhu¹Yan Wang¹Lirong Zhao¹Wenli Wang¹Ge Li³Fei Wang^1,4Xiaohua Wang^1*

• ¹Inner Mongolia Maternal and Child Health Care Hospital, Huhhot, China
• ²School of Public Health, Peking University, Beijing, China
• ³School of Health, Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China
• ⁴Shandong Provincial Hospital, Jinan, Shandong Province, China

Background: Phenylketonuria (PKU) is a hereditary metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene, leading to the accumulation of phenylalanine (Phe) in the blood. Without timely treatment, PKU patients may develop irreversible intellectual and neurocognitive deficits. The primary treatment for PKU is a strict low-Phe diet, which must be initiated in early life to achieve better outcomes. Therefore, parents and parents' caregivers play a crucial role in dietary management. However, poor dietary adherence and inadequate health knowledge significantly affect treatment efficacy. Mobile health (mHealth) interventions, as an emerging health management approach, offer personalized, low-cost, and highly accessible solutions. This study aims to develop and evaluate an mHealth intervention model based on the Behavior Change Wheel (BCW) theory and family health theory to improve health management for children with PKU. Methods: This single-center, single-blind randomized controlled trial will be conducted at the Inner Mongolia Maternity and Child Health Care Hospital in China from March to September 2025. Participants will include children with PKU and their parents' caregivers, who will be randomly assigned to either the intervention group (receiving mHealth interventions via WeChat) or the control group (receiving routine health education). The intervention will include health education, dietary management, regular monitoring reminders, and online consultation services. The primary outcome will be the serum phenylalanine and tyrosine levels of the children. Secondary outcomes will include nutritional indicators, intellectual development indicators, and the caregivers' health knowledge, compliance, and mental health. Data collection will occur at baseline and at 3 and 6 months post-intervention. Discussion: By integrating the BCW and family health theories, this study innovatively develops an mHealth-based health management intervention model for PKU. This model is expected to enhance family health management capabilities and improve clinical outcomes and quality of life for children with PKU. If effective, this model can be extended to other regions to provide more convenient and efficient health management solutions for PKU patients.