Let's Grow: Evaluating the efficacy of a mobile-web app on sedentary behaviour, physical activity and sleep in 2-year-old children.

The intervention content will be delivered via a mobile web app (named “Let’s Grow”) and SMS notifications. Participants in the intervention group will work through eight modules within the app in their own time over 12 months. There will be 'refresher' notifications pushing participants back to the app for those who complete the modules in less than 12 months. Each module contains content on parenting and a combination of behaviours (physical activity, sedentary behaviour and sleep), highlighting the interplay between the behaviours in line with the 24-hour movement paradigm (e.g. replacing screen time with active play). In addition, core content is contained within a ‘toolkit’ e.g. parenting strategies, active play ideas, screen free ideas, common sleep issues. Intervention content has been developed by a team of experts and incorporates practical advice, established behaviour change techniques (e.g., goal setting, self-monitoring), and tips and tools to assist parents/caregivers to improve their child’s physical activity, sleep and sedentary behaviour. This includes information about the behaviours, guidelines in early childhood, ideas for promoting each of the behaviours, parenting strategies, and tasks to put participant learning into action, e.g., quizzes, goal setting, self monitoring, creation of routines. Information will be presented using text, infographics, animations and live action videos. The app will also contain a social forum that parents will have the option to participate in should they wish to. Module content takes approximately 10min to read/view; the interactive tasks conducted offline with assistance from notifications are undertaken over a period of 2-5 weeks (e.g. goal setting) per module. Parents will also receive SMS notifications over the course of the intervention to assist with monitoring progress of ongoing activities (e.g. goal setting and self monitoring), to remind them of key messages, and to push them back to app content. Notifications will be personalised to include the parent and child names and their chosen goal/s (where appropriate). Intervention adherence will be monitored by app usage data. Automated notifications will be sent after predetermined periods of app inactivity to encourage participants to re-engage and complete the program. If there is continued inactivity after two automated notifications, research staff will contact participants to encourage continuation of the program.