Acceptability and Usability of a Mobile Health App for Family Obesity Prevention and Management: A Mixed-Methods Feasibility Study

Background: Digital tools are being used to support the prevention and management of childhood obesity, a global public health concern. The aim of this study was to evaluate the usability, acceptability, perceived impact, and potential for adoption and sustainability of a digital health app for childhood obesity management. Methods: In this phase 1 mixed-methods pilot study, we recruited parents/guardians with children of any age and weight, healthcare professionals, and Health Education England employees. Semi-structured interviews, questionnaires, and app use data were used to assess users’ experiences with the app; perceived impact on motivation, self-efficacy, and behaviours; usability (System Usability Scale); factors related to adoption and sustainability. Analysis was based on two conceptual frameworks: the Reach Effectiveness Adoption Implementation Maintenance (RE-AIM) and Non-adoption, Abandonment and Challenges to the Scale-up, Spread and Suitability (NASSS) frameworks. The study took place between March 2020 and April 2021. Findings: Of 225 parents/guardians recruited, 61 (27%) responded to the demographic survey and 85 (38%) responded to the final survey. We also interviewed 15 parents/guardians. Thematic analysis of those interviews identified three themes about users’ experiences: positive and negative feedback and suggestions for improvement. Overall, participants reported that goal-setting, prompts, and suggestions helped support their awareness, motivation, and self-efficacy to pursue healthier behaviours. Motivation was bolstered by the app’s prompts and suggestions, but sustained engagement was limited by a lack of novel content. Key suggestions included more content and improved notifications and progress tracking. Usability scores were ‘average’ (M =70·3/100, 95% CI: 63·8-76·8). Interpretation: Mobile health apps have the potential to support behaviour change, and feedback from healthcare professionals could further improve families’ motivation and self-efficacy to achieve behavioural goals. Trial Registration Details: This study is registered at ClinicalTrials.gov (NCT05261555). Funding Information: This research was funded by Health Education England (grant reference number: AM1000393). Declaration of Interests: ER and AP are employees of Health Education England and were involved in the development of the NoObesity apps. ER and AP contributed qualitative data and reviewed the final manuscript prior to submission, but the academic authors retained editorial control. Ethics Approval Statement: Ethical approval was obtained from the University of Oxford Medical Sciences Interdivisional Research Ethics Committee (R62092/RE001) and the University of Plymouth’s Faculty Research Ethics and Integrity Committee (19/20-1316).