RESUMEN
Objective@#To study the compliance and associated factors of smartphone application (APP) usage in childhood dietary and exercise intervention.@*Methods@#Based on one childhood intervention of diet and exercise in Beijing, Changzhi of Shanxi Province and Urumqi of Xinjiang Province, 694 children (and their primary caregivers) in the intervention group were investigated regarding usage of APP during the intervention. Compliance of APP usage was evaluated by the click times of APP, and Logistic regression models were used to analyze influencing factors of the compliance.@*Results@#The median (inter quartile range) click times of APP in the four modules (information dissemination, behavior monitoring, homework uploading and feedback) were 10 (5，21), 20 (14，26), 7(4，10), 26 (15，53), respectively. Multivariable logistic regression analysis found that compliance of APP usage was higher among subjects in Changzhi region ( OR =1.67，95% CI =1.12-2.48), whose primary caregiver was mother ( OR =1.55，95% CI =1.09-2.22), or whose mother did not work ( OR =0.47， 95% CI =0.31-0.74).@*Conclusion@#Compliance of APP usage was generally high in the childhood intervention of diet and exercise. Some factors are associated with compliance of APP usage. Findings of the study provide a scientific basis for better implementation of APP based childhood interventions of diet and exercise in the future.