Planning with a partner? Individual and dyadic planning in three health behaviour contexts

IV Abstract Health behaviours such as fruit and vegetable intake as well as physical activity are related to reduced risk for specific diseases (e.g., cardiovascular diseases, cancer) and allcause mortality. Despite the importance to engage in these health behaviours regularly, the majority of German adults do not adhere to such public guidelines. Empirical evidence shows that many individuals fail to translate their health-behaviour-related intentions into action. In health behaviour change theories, individual planning is suggested as an important self-regulatory strategy to bridge this intention-behaviour gap. That is,Health behaviours such as fruit and vegetable intake as well as physical activity are related to reduced risk for specific diseases (e.g., cardiovascular diseases, cancer) and allcause mortality. Despite the importance to engage in these health behaviours regularly, the majority of German adults do not adhere to such public guidelines. Empirical evidence shows that many individuals fail to translate their health-behaviour-related intentions into action. In health behaviour change theories, individual planning is suggested as an important self-regulatory strategy to bridge this intention-behaviour gap. That is, individuals form plans on when, where, and how to perform a behaviour. An example plan for the enhancement of physical activity would read “When I come home from work, then I will go jogging for 30 minutes” (When: after work; Where: home as the starting point; Behaviour: Jogging; How: for 30 minutes). Moreover, as health regulation is strongly affected by our social environment, the conceptualisation dyadic planning was introduced, that is, planning one’s health behaviour together with a partner. This thesis starts with introducing the literature on individual planning, followed by reviewing empirical evidence on individual planning and dyadic forms of planning. To further contribute to research on health behaviour-related individual and dyadic planning, the following research questions will be investigated (summarised). 1) How frequently are individual and dyadic planning used at baseline and over time? (Chapters 2 to 5) 2) How are psychosocial predictors linked to dyadic planning? (Chapter 2) 3) Which behavioural links show individual and dyadic planning and how do these links change over time? (Chapter 3) 4) Which mechanisms of an individual planning intervention explain health behaviour changes? (Chapter 4) Abstract IV 5) Which plan characteristics of individual and dyadic plans are associated with planIV 5) Which plan characteristics of individual and dyadic plans are associated with plan enactment? Which enactment rates show individual and dyadic plans? (Chapter 5) The data to answer these questions come from three study projects investigating three health contexts and samples: prostate cancer patients’ post-surgery rehabilitation and their partners (Chapters 2 and 3), adult individuals’ fruit and vegetable consumption (Chapter 4), and adult couples’ physical activity (Chapter 5). The results of the empirical chapters lead to the following answers to the research questions (1) to (5). 1) Participants used individual planning more often than dyadic planning (Chapters 2 to 5). Regarding planning use over time, individual and dyadic planning of rehabilitative exercises were used more frequently in the beginning, but less frequently at later stages of prostate cancer patients’ rehabilitation. 2) Relevant unique predictors of prostate cancer patients’ dyadic planning of rehabilitative exercises were patients’ positive affect and self-efficacy, patients’ and their partners’ relationship quality, as well as partners’ reports on patients’ urinary incontinence severity (Chapter 2). 3) Individual planning was a constant and positive correlate of prostate cancer patients’ rehabilitative exercise. Dyadic planning became more important for PFE at later stages of rehabilitation (Chapter 3). 4) Improved levels of persons’ intentions following an individual planning intervention was the most important predictor of fruit and vegetable consumption (Chapter 4). 5) For both individual and dyadic plans, plan enactment was more likely in earlier plans, when plans included a routine, and when the time-cue was less specific. Dyadic plans were more likely enacted as compared to individual plans (Chapter 5). In the general discussion, these results are integrated into the literature on health behaviour-related planning and implications for research and practice are discussed. In conclusion, this thesis fills important gaps in the literature by comprehensively Abstract IV investigating dyadic planning as a predictor of health behaviour, as an outcome ofIV investigating dyadic planning as a predictor of health behaviour, as an outcome of psychosocial constructs, and as an active ingredient of interventions.