Understanding the barriers to lifestyle change in the SPHERE study

  • Judith Cole

Student thesis: Doctoral ThesisDoctor of Philosophy



Interventions designed for the secondary prevention of coronary heart disease, which include a lifestyle of regular physical activity and a healthy diet, are known to improve life expectancy. However, adherence to recommended lifestyle changes is difficult for many patients. The aim of this thesis was to explore lifestyle change interventions in patients with cardiovascular disease and ways of improving their effectiveness.


To investigate the effectiveness of lifestyle interventions for the secondary prevention of coronary heart disease, a systematic review was performed. Three databases were searched and the effect of interventions on mortality, morbidity, non-fatal events and lifestyle risk factors was investigated. Meta analyses of results were performed.

The problem of adherence to healthy lifestyles was investigated in detail in one such intervention. A sample of patients who took part in the SPHERE Study, from practices in Belfast, Dublin and Galway, was selected and semi structured interviews conducted. Interviews were analysed qualitatively and themes relating to barriers and facilitators to lifestyle change were sought.

The findings of this qualitative study were used to design a shared decision making tool, the aim of which was to motivate patients to consider making lifestyle changes. Based on barriers and facilitators found in the previous study, questions were designed and the tool was tested in a feasibility study among 12 patients from two purposively selected practices.


The systematic review demonstrated that interventions have significant benefits in terms of total and cardiac mortality, and in relation to lifestyle behaviour change.

A wide range of barriers and facilitators affecting lifestyle change was presented in the qualitative study. Novel barriers included the strong negative influence of social networks, linked to cultural norms and others' lack of perception of the adverse impact on change of presents of chocolates and 'delicious' but unhealthy food. The importance of a trusted patient-professional relationship was highlighted to a unique extent with patients demonstrating the value of personalised support.

The decision making tool was welcomed by patients in the feasibility study. An aim of the tool was to stimulate conversation between the patient and professional and this was demonstrated effectively. The patients were stimulated to think and talk about their daily lives, their routines, contact with other people, likes and dislikes in relation to PA and diet, beliefs, hopes and fears. Patients suggested amendments to the tool which were used to refine its design.


Healthy lifestyles should be promoted to adults who have suffered a coronary event, however care should be taken to understand patients' daily routines, social environments and concerns - and to help them overcome specific barriers. A shared decision making tool may help patients focus on their lifestyle and to discuss with a professional how to make positive changes. The findings of this thesis could be used to design efficient and effective interventions in the future.
Date of AwardDec 2012
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorMargaret Cupples (Supervisor), Nigel Hart (Supervisor) & Susan Smith (Supervisor)

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