Using virtual representations in mHealth application interventions for health-related behaviour change: A systematic review

Many mobile health (mHealth) application interventions include virtual representations of the self in varying forms, such as agents, or avatars to initiate health behaviour change. This review aimed to determine: (i) which virtual representations are effective in mHealth application interventions, and (ii) whether any studies implemented specific mechanisms (the psychological causes of change) and behaviour change techniques (BCTs) to influence positive behaviour change. Following PRISMA guidelines, a narrative systematic review of empirical studies was conducted from ten different databases (ranging from MEDLINE to Cochrane Library) from inception to December 2021. This included articles reporting a virtual representation of mHealth application intervention, published in English from any time point, which addressed and reported a variety of outcome health behaviours. Information on sample characteristics, study conditions, mechanisms and BCTs, results, and conclusions were extracted. Quality and risk of bias were assessed using the Mixed Methods Appraisal and Cochrane Risk of Bias Tools. Out of the 2,579 original search results, five eligible studies (total participants = 509), with low to moderate quality were included. It was found that customisable virtual representation mHealth interventions were most effective in encouraging behaviour change and app adherence. These interventions included mechanisms such as motivation, feedback, self-image, and BCTs such as goal setting, and self-monitoring. The current evidence suggests that virtual representations in mHealth app interventions may positively influence health behaviour change. However, there is limited evidence available to determine to which these influences are a result of the virtual representations, or the intervention design