The aims of this study were to evaluate the long-term effectiveness of the Care & Organize Our Lifestyle (COOL) program, a self-regulation theory-based mHealth program, on improving disease knowledge and physical activity in youth with congenital heart disease (CHD). The COOL program is a 12-month randomized controlled trial that compared two active intervention groups to a standard-care control group (n = 47). Participants with simple and moderate CHD aged 15-24 years were recruited from pediatric or adult CHD outpatient departments. Participants in one active intervention group (n = 49) were provided with COOL Passport, a mobile healthcare application. Those in the other group (n = 47) were provided with access to the Health Promotion Cloud system and use of game-based interactive platforms along with COOL Passport. Outcomes were the Leuven Knowledge Questionnaire for CHD and the International Physical Activity Questionnaire-Taiwan Show-Card Version.

Background: Mobile health initiatives may provide youth with congenital heart disease (CHD) relevant health information and a platform for managing the complex health care needs associated with undergoing transitional care.

Aims: To evaluate the long-term effectiveness of the Care & Organize Our Lifestyle (COOL) program, a self-regulation theory-based mHealth program, on improving disease knowledge and physical activity in youth with CHD.

Methods: The COOL program is a 12-month randomized controlled trial that compared two active intervention groups to a standard-care control group (n = 47). Participants with simple and moderate CHD aged 15-24 years were recruited from pediatric or adult CHD outpatient departments. Participants in one active intervention group (n = 49) were provided with COOL Passport, a mobile healthcare application. Those in the other group (n = 47) were provided with access to the Health Promotion Cloud system and use of game-based interactive platforms along with COOL Passport. Outcomes were the Leuven Knowledge Questionnaire for CHD and the International Physical Activity Questionnaire-Taiwan Show-Card Version.

Inclusion Criteria:

• being diagnosed with CHD by a pediatric cardiologist and qualifying as having simple or moderate CHD complexity according to the 2008 American College of Cardiology/American Heart Association guidelines;
• having a regular pulse;
• being 15-24 years of age;
• being conversant in Mandarin and Taiwanese;
• possessing a smartphone with Internet connection;
• agreeing to wear an exercise-monitoring wristband to record physiological data;
• agreeing to engage in exercises designed to test cardiopulmonary endurance;
• agreeing to participate in the study and sign an informed consent form for a relevant interview. For participants under 20 years of age, guardian approval by signing a written consent form was required.

Exclusion Criteria:

• having cognitive impairment to the extent of being noncommunicative;
• having CHD complicated with other congenital abnormalities;
• having undergone a cardiac catheter-related intervention or surgery within the past 6 months;
• being pregnant