The conceptual HABITS prototype for integrating behavioural theories with system dynamics and agent-based models to capture complex health behaviours

Healthcare simulation models often rely on oversimplified assumptions about health behaviour, potentially undermining their predictive power and policy relevance. This paper systematically reviews how behavioural theories have been incorporated into healthcare simulation models and proposes HABITS (Health Behaviour Integrated Theory-based Simulation), a conceptual prototype combining advances in simulation modelling and behavioural science. Our research reveals that current approaches suffer from ad-hoc theory selection, overemphasis on behaviour change initiation over maintenance, and neglect of crucial areas, including health systems management, non-communicable-disease self-management, and provider behaviours. Most studies target motivation and opportunity drivers of health behaviour while overlooking capacity enhancement and broader social determinants. HABITS is designed to address these limitations by integrating the COM-B (Capability, Opportunity, Motivation-Behaviour) model with hybrid simulation approaches, providing structured guidance for incorporating behavioural determinants across system, social, and individual levels while capturing between-level feedback. This integration enables operationalisation of the Behaviour Change Wheel, allowing systematic development and evaluation of interventions and policies. This prototype aims to enhance design transparency, facilitate cross-study comparisons, and improve communication across disciplines and with stakeholders. Future research should explore theory-data integration and synergies between behavioural theories and emerging technologies such as Large Language Models to develop more robust, predictive models.