Buddy-Motivational Interviewing (buddy-MI) to increase physical activity in community settings: A pragmatic randomised controlled trial
Thesis DisciplineHealth Sciences
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Populations in developed and developing countries are becoming increasingly sedentary and the adverse health effects of relatively sedentary lifestyles, the so called lifestyle diseases, are now obvious. However, moderately vigorous physical activity is positively linked via a cause-and-effect relationship with a range of improved health outcomes. Broadly, current physical activity recommendations suggest that adults should achieve a total of at least 30 minutes a day of at least moderate intensity physical activity on five or more days of the week; however, estimates suggest that the majority of adults in the Western World do not meet these recommendations. Many of the factors involved in the initiation and long-term maintenance of physical activity are not fully understood. Considering the rapid pace of technological development and the general move away from labour-based economies, it does appear that the required level of physical activity necessary for optimal health needs to come from leisure-time activity– specifically, planned, regular, moderately vigorous exercise and/or sport. Unfortunately, many people experience great difficulty in engaging with and maintaining a physically active lifestyle and typically there is a rather large gap between what people know to be healthy and what they actually do. The general aim of this project was to design, implement and evaluate the clinical, social and behavioural effectiveness of a buddy-Motivational Interviewing intervention (buddy-MI) in assisting relatively sedentary adults to adopt and maintain regular physical activity for the purpose of improving their cardio-respiratory fitness, health, and quality of life. Specific aims of the intervention included formally involving social support (via the self-selected motivational-buddy) and strengthening individuals’ motivation for and movement toward their physical activity goals. The experimental intervention specifically aimed to extend the MI treatment effect by enhancing participants’ commitment to physical activity over time via intra-treatment social support (support provided within treatment sessions) as well as extra-treatment social support (day-to-day support) provided by the motivational-buddy. A fundamental was to deliver the intervention in a format that could realistically be implemented within typical primary care settings, workplaces, schools or other similar setting: to work towards healthier more active communities and to potentially reduce health system resource utilisation. Using a repeated-measures pragmatic parallel group randomised controlled trial (RCT) design, relatively sedentary adolescents and adults, in stable health, recruited from a university campus population were allocated to one of two interventions. In the experimental intervention, participants were supported by a self-selected motivational-buddy and they received 2-4 sessions of buddy-MI over a period of 12-months (participant determined schedule) as well as pro-active follow-up emails. The control intervention was standard care MI, and the same email follow-up as in the experimental group but without the additional support of a motivational-buddy. The main outcomes were self-reported physical activity, cardio-respiratory fitness and health related quality of life. These primary outcomes were measured at four time-points over the 12-months intervention and follow-up period and quantitative methods were used to analyse the data. Qualitative data were also analysed and presented in relation to the motivational-buddy component of the intervention. The study evaluated the feasibility and incremental effectiveness of motivational-buddy support compared to one-on-one MI in people who had expressed an interest in becoming more physically active. It used a novel intervention design incorporating self-selected motivational-buddies in an effort to mitigate the twin problems of poor adherence and behavioural regression that are commonly associated with physical activity promotion programmes. The intervention was found to have merit and the potential implications for the health-care system, and the wider community, are discussed.