Unlocking the Potential of mHealth: Integrating Behaviour Change Techniques in Hypertension App Design

<b>Background:</b> Smartphone apps offer a promising avenue for delivering scalable interventions for hypertension self-management. This study aimed to characterise the behaviour change technique ontology (BCTO) elements present in apps available on popular platforms, map the theoretical domains framework (TDF), and describe the apps' functionalities. <b>Methods:</b> A comprehensive search of app stores was conducted to identify relevant hypertension self-management apps. The identified apps were then analysed for BCTO elements, which were subsequently mapped to TDF. App functionalities and quality were assessed as well. <b>Results:</b> Functionalities such as self-monitoring were consistently observed across all app types, aligning with established hypertension self-management strategies. However, other key functionalities, including goal setting via reminders, communication with healthcare professionals, and data export capabilities, were less prevalent. AI-empowered apps incorporated a broader range of behaviour change techniques compared to non-AI and RCT-tested apps, suggesting a potentially more comprehensive approach to supporting behaviour change. The domains of "Knowledge", "Emotions", "Behavioural regulation", "Skills", and "Beliefs about Consequences" were most frequently targeted by app developers. AI-empowered apps incorporated a broader range of BCTs compared to non-AI and RCT-tested apps, potentially offering more comprehensive support for behaviour change. <b>Conclusions:</b> While existing hypertension self-management apps incorporate a variety of BCTs, there is room for improvement in terms of incorporating a wider range of functionalities and BCTOs, particularly those targeting more intrinsic and habitual aspects of behaviour.