See How They Grow: Testing the Feasibility of a Mobile App to Support Parents' Understanding of Child Growth Charts

Background: Mobile devices provide new opportunities for the prevention of overweight and obesity in children. We aimed to co-create and test an app that provided comprehensible feedback to parents on their child's growth and delivered a suite of age-specific information about nutrition and activity. Methods: A two-phased approach was used to co-create the digital growth tool - See How They Grow - and test its feasibility. Phase one used focus groups and a national online survey to gather requirements and build the app.  Phase two involved testing the app over 12-weeks, with parents or carers of children aged ≤ 2-years.  All research activities were undertaken exclusively through the app.  Participants were recruited using social media and hard copy materials.  Findings: Four focus groups and 101 responses to the national survey informed the features and functions to include in the final app.  Two hundred and twenty-five participants downloaded the app, resulting in 208 eligible participants. Non-Māori/Non-Pacific (78%) and Māori (14%) had the highest downloads. Fifty-four per cent of participants were parents of children under 6-months.  These participants were more likely to regularly use the app than those with children older than 6-months (64% vs 36%, P =0.011).  Over half of the participants entered three measures (n=101, 48%).  Of those that completed the follow-up survey (n=101, 48%), 72 reported that the app helped them better understand how to interpret growth charts. Interpretation: With minor modifications, the app could be an effective tool to support parents understanding of growth trajectories and what they mean for their children. A larger trial is needed to evaluate if the app can have a measurable impact on increasing knowledge and behaviour, and therefore on preventing childhood overweight and obesity. Funding Statement: This study was funded through a contestable funding round by Cure Kids, the National Science Challenge: a Better Start and Precision Driven Health. The funders had no influence on the design, implementation, interpretation or reporting of the study findings. Declaration of Interests: None. Ethics Approval Statement: The study has Ethics approval from the NZ Auckland University Human Participants Ethics Committee; Co-creation and Development Study Reference 020166, Feasibility Study Reference 022248. All participants gave consent to participate. The feasibility study was registered on the Australia New Zealand Clinical Trial registration (ACTRN12619000905167).