Developing a Taxonomy of Dyadic Behavior Change Techniques ------------------------------------------------------------------------ **Corina Berli (PI)**, University of Zurich, Department of Psychology, Applied Social and Health Psychology **Urte Scholz (Co-PI)**, University of Zurich, Department of Psychology, Applied Social and Health Psychology **Nina Knoll (Co-PI)**, Freie Universität Berlin, Department of Education and Psychology, Division of Health Psychology **Gertraud Stadler (Co-PI)**, Charité - Universitätsmedizin Berlin, Institute of Gender Medicine *Investigators:* **Karoline Villinger**, University of Zurich, Department of Psychology, Applied Social and Health Psychology **Sally Di Maio (Investigator)**, Freie Universität Berlin, Department of Education and Psychology, Division of Health Psychology *Project Partner:* **Caterina Gawrilow**, Eberhard Karls Universität Tübingen, Department of Psychology, School Psychology ---------- **Summary of the research plan** Health-enhancing behaviors such as being physically active, eating healthily, or using condoms as well as health-compromising behaviors such as smoking or excessive alcohol consumption often have a social component. Likewise, a growing literature documents the importance of the social context in shaping health behavior change. Particularly for one of the closest personal relationships during the adult lifespan, the relationship with a romantic partner, researchers have produced a large number of theories and empirical findings to better understand the protective effect of close relationships on health. However, despite decades of research, the specific processes underlying the powerful effect of romantic relationships on health are still far from understood. This broad research field, including disciplines within psychology (e.g., health, social, clinical psychology, relationships research) as well as beyond (e.g., sociology, economics, health sciences), has produced a highly heterogeneous nomenclature and a myriad of constructs of different complexity, hampering the synthesis of empirical evidence. At the same time, there has been a rise in dyadic intervention studies, many of which involve couples to change health behavior. Overall, evidence to date suggests that dyadic interventions in romantic couples are a promising avenue for changing health behavior. However, due to poor reporting of intervention content and unsystematic labeling of intervention strategies, little is known about what exactly makes these interventions successful. In recent years, there has been considerable effort to systematically identify and classify intervention techniques used to promote health behavior change to facilitate accumulation of evidence. Yet, the majority of behavior change techniques identified in existing taxonomies are at the level of the individual (e.g., goal setting, self-monitoring), and intervention techniques involving any form of interaction with a non-professional dyad member (i.e. dyadic behavior change techniques) are underrepresented or not well differentiated (see the preliminary list of selected dyadic behavior change techniques (DBCTs) as part of this OSF project). Thus, to understand dyadic processes in health behavior change, a systematic and reliable identification of dyadic behavior change techniques presents an important next step. This project “Developing a Taxonomy of Dyadic Behavior Change Techniques”, funded as a D-A-CH lead agency project by the Swiss National Science Foundation (lead agency; 10001CL_192438) and the Deutsche Forschungsgemeinschaft (KN 937/5-1; STA 1693/1-1) strives to tackle this issue. We aim to develop and evaluate a comprehensive and reliable taxonomy of theory-based distinct, clear and precise dyadic behavior change techniques (DBCTs) to change a person’s health-enhancing (e.g., physical activity, nutrition) or health-compromising (e.g., smoking, alcohol consumption) behaviors. We will use the example of romantic couples as a highly important dyad for health behavior change. By drawing on a network of international experts, we aim to establish an internationally accepted taxonomy that will ensure precise reporting of dyadic intervention content, guide the development of theory-based dyadic behavior change interventions, and facilitate evidence synthesis across disciplines on effective dyadic behavior change in romantic couples. This will lay a solid foundation for establishing future DBCT taxonomies for other dyad constellations (e.g., parent-child, buddies, peers) or contexts (e.g., mental health, stress, marital functioning). *Aims and Research Goals* The aim of this project is to develop and evaluate a taxonomy that comprises a comprehensive list of clearly labelled, well defined, and theory-based dyadic behavior change techniques (DBCTs). We define dyadic behavior change techniques (DBCTs) as an observable and replicable theory-based intervention technique that explicitly involves any form of interaction with a non-professional dyad member to change behavior, either with one partner (‘cross-over’) or both partners (‘joint’) actively involved in implementing the intervention task (cf. Scholz et al., 2020; and see Figure in this OSF project). The initial focus is on romantic couples as a particularly relevant dyad for understanding the effects of close relationships on health and well-being that has a rich as well as interdisciplinary theoretical and empirical literature. The DBCTs are used as active ingredients in dyadic interventions with romantic couples to change the health behavior of at least one partner in two domains: a) health-enhancing behaviors (e.g., physical activity, healthy eating, medication adherence) and b) health-compromising behaviors (e.g., smoking, alcohol consumption, sexual risk behavior). The taxonomy will lay an important foundation for other or more extended versions of DBCT taxonomies across different dyad constellations and/or behavioral contexts (i.e., other than health behaviors), similar to the development of the comprehensive BCTTv1 (Michie et al., 2015). The taxonomy strives to provide DBCTs that are distinct and precise, enabling accurate reporting of intervention content, and being accepted across disciplines (e.g., health, social, clinical psychology, relationships research). The DBCT taxonomy seeks to primarily serve as a description and classification of dyadic behavior change techniques existing in theory and empirical literature, thus, allowing for detailed and reliable reporting of intervention content. As an important addition, in the DBCT taxonomy each technique will be contextualized within its explicit theory of origin and linked to the theoretical determinant(s) it is trying to change, or where not possible, reported as such. Theoretical determinants have been defined as “generic modifiable psychological variables or regulatory processes that are assumed, on the basis of empirical or theoretical evidence, to be causal antecedents of behavior (p. 299)” (Kok et al., 2016). This will allow researchers to target psychological determinants more deliberately and to better evaluate the process underlying effective interventions (see Michie et al., 2018). With this, the taxonomy aims to integrate the approaches of an intervention coding as well as intervention development taxonomy (cf. Kok et al., 2016), which is an important next step in identifying and classifying dyadic behavior change techniques. A sequence of three phases is proposed to achieve the project’s aim. **Goal of Phase 1**: The goal of the convergence phase (Phase 1) is to develop a prototype taxonomy. This will be based on dyadic behavior change techniques used in existing dyadic interventions with romantic couples to promote health-enhancing behaviors and to reduce health-compromising behaviors (bottom-up). Techniques will further be extended and refined based on expert input and relevant theoretical literature and intervention / program manuals (top-down), also from related fields with a focus on health behavior change. **Goal of Phase 2**: The goal of the divergence phase (Phase 2) is to achieve an agreed-upon taxonomy of theoretically-derived, clearly labelled and precisely defined dyadic behavior change techniques through expert consensus. **Goal of Phase 3**: The goal of Phase 3 is to evaluate initial reliability of the taxonomy in identifying dyadic behavior change techniques in existing intervention descriptions, drawing upon intervention studies from the convergence phase (Phase 1). ---------- *Expected contribution* This research project will have numerous scientific merits. Establishing a taxonomy of theoretically-derived dyadic behavior change techniques in couples that is accepted across disciplines will have the potential to 1) harmonize between different nomenclatures across multiple disciplines, 2) enhance precision of reporting of dyadic intervention content and with this, promote accurate replication of intervention techniques which is key to accumulating scientific knowledge and investigating generalizability across behaviors, 3) inform and guide the development of dyadic interventions drawing on a comprehensive list of clearly defined, theoretically-derived dyadic behavior change techniques, potentially increasing the use of more diverse dyadic behavior change techniques to promote health behavior, 4) allow to synthesize evidence from complex, and heterogeneous dyadic interventions and to establish effectiveness of specific dyadic behavior change techniques. This will support reliable accumulation of knowledge regarding the dyadic techniques of couple-based interventions, and inform the causal processes involved in explaining the survival benefit of individuals in romantic relationships. Importantly, the proposed project represents the first stages of a program of research, aiming to demonstrate ‘proof of principle’ rather than to produce a finished and inalterable product, similar to how existing taxonomies (Kok et al., 2016; Michie et al., 2013) have been progressively developed. The aim of the DBCT taxonomy, using the exemplary case of romantic couples, is to build a solid basis for cross-validations with other dyad-constellations (e.g., parent-child, buddies, peers). It will lay a robust foundation for subsequent or more comprehensive taxonomies across dyad constellations as well as other contexts (e.g., mental health, stress, marital functioning). ---------- **References** Kok, G., Gottlieb, N. H., Peters, G.-J. Y., Mullen, P. D., Parcel, G. S., Ruiter, R. A. C., . . . Bartholomew, L. K. (2016). A taxonomy of behaviour change methods: An intervention mapping approach. Health Psychology Review, 10(3), 297–312. https://doi.org/10.1080/17437199.2015.1077155 Michie, S., Carey, R. N., Johnston, M., Rothman, A. J., Bruin, M. de, Kelly, M. P., & Connell, L. E. (2018). From theory-inspired to theory-based interventions: A protocol for developing and testing a methodology for linking behaviour change Techniques to Theoretical Mechanisms of Action. Annals of Behavioral Medicine, 52(6), 501–512. https://doi.org/10.1007/s12160-016-9816-6 Michie, S., Richardson, M., Johnston, M., Abraham, C., Francis, J., Hardeman, W., . . . Wood, C. E. (2013, August). The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques: Building an international consensus for the reporting of behavior change interventions. Annals of Behavioral Medicine, 46(1), 81–95. https://doi.org/10.1007/s12160-013-9486-6 Michie, S., Wood, C. E., Johnston, M., Abraham, C., Francis, J. J., & Hardeman, W. (2015). Behaviour change techniques: The development and evaluation of a taxonomic method for reporting and describing behaviour change interventions (a suite of five studies involving consensus methods, randomised controlled trials and analysis of qualitative data). Health Technology Assessment, 19(99), 1–188. https://doi.org/10.3310/hta19990 Scholz, U., Berli, C., Lüscher, J., & Knoll, N. (2020). Changing behavior using dyadic interventions. In M. S. Hagger, L. Cameron, K. Hamilton, N. Hankonen, & T. Lintunen (Eds.), The Handbook of Behavior Change. Cambridge, UK: Cambridge University Press.