Design and methods of the StepByStep randomized trial of a mobile health and social media physical activity intervention among adolescent and young adult survivors of childhood cancer: A report from the Children's Oncology Group.

BACKGROUND: Interventions to increase physical activity are needed in adolescent and young adult survivors of childhood cancer who are largely inactive but at lifelong elevated risk of multiple chronic conditions improved by physical activity. The goals of the StepByStep study are to evaluate the effects of a 48-week distance-based, multi-component mobile health and social media behavioral intervention on physical activity, biomarkers of cardiometabolic health, and health-related quality of life. METHODS: This ongoing study is a two-arm, prospective, multi-site randomized controlled trial. 384 childhood cancer survivors age ≥ 15 years and < 21 years who were 3-36 months off therapy and not meeting physical activity guidelines were enrolled. The trial will test the efficacy of a 24-week intensive multi-component physical activity intervention combining a wearable physical activity tracker, social media peer support group, and individualized goal setting followed by a 24-week maintenance phase of the intervention to improve outcomes. The control group receives the wearable physical activity tracker only. CONCLUSION: There is a growing need for novel, developmentally appropriate interventions to increase physical activity and improve the health trajectory of adolescent and young adult survivors of childhood cancer. If efficacious, this portable and scalable intervention would be a much-needed tool to reduce the morbidity from cancer treatment and improve quality of life among survivors after treatment ends. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04089358; COG Identifier: ALTE2031.