Evaluating the implementation of Smile4life
: a theoretically driven exploration

  • Laura Beaton

Student thesis: Doctoral ThesisDoctor of Philosophy


My thesis is a theoretically informed evaluation of the implementation of an ongoing national policy intervention: Smile4life, Scotland’s national oral health improvement programme for people experiencing homelessness. This work was initially conceived following a process evaluation of Smile4life implementation, which revealed that Smile4life practitioners working in NHS Boards varied in the speed of their adoption of the programme and in how they implemented Smile4life. This original work (Beaton and Freeman, 2016) uncovered certain questions relating to the practitioners’ working behaviours and the role of policy and organisational level factors associated with implementation. Therefore, the basis of the research was to delve deeper, using a theory-informed approach and to understand and evaluate how Smile4life was being implemented from a range of perspectives, including Smile4life practitioners and NHS Board oral health managers. The overall aim was to evaluate the live implementation of this ongoing policy intervention, by identifying the organisational and practitioner factors that influence the delivery and implementation of Smile4life.

Following a narrative review of health and homelessness policy and a scoping review of oral health and homelessness interventions, this thesis details the theoretical, methodological and ethical considerations of this research before presenting the four studies that form the main part of this work. A range of qualitative and quantitative methods were used, and theories adopted, to inform the data collection and data analysis over a series of four studies, to achieve the aim of the thesis and examine the complexity of Smile4life behaviours from various perspectives. The adoption of different theoretical lenses and a mixed methods approach reflected the complexity of the Smile4life intervention and enabled the ability to adapt to the changing nature of the intervention as the research proceeded. Each study will now be summarised in turn.

Study 1: A participant observation study was conducted, to observe working behaviours of Smile4life practitioners and establish how Smile4life was being implemented. The data from this study were analysed taking into consideration the theories related to triadic coalitions and working alliances. This study found that Smile4life practitioners who formed triadic working alliances with Third Sector staff and homeless service users successfully implemented the Smile4life programme. From the observations that a triadic alliance was essential for Smile4life implementation, it was decided to conduct focus groups with Smile4life practitioners to see if the observations noted in Study 1 were experienced by these staff.

Study 2: Focus group discussions were conducted to determine the influence of the Smile4life intervention on the engagement behaviours of Smile4life practitioners. The focus groups asked participants about their Smile4life work and experiences; the qualitative data analysis was theory-informed by the COM-B model from the Behaviour Change Wheel, (Michie et al., 2011), a framework for characterising behaviour change interventions which can be used to inform improvements to the design of interventions and their implementation. This study concluded that the Smile4life intervention promoted practitioners’ capability, opportunity and motivation which in turn fostered engagement behaviours and, for those practitioners with specific personalities and work experiences, lead to spanning boundaries between disciplines. However, while Studies 1 and 2 had concentrated upon frontline practitioners, a question remained about the organisational factors associated with implementing Smile4life at an NHS Board level.

Study 3: The third study, therefore, was conducted with oral health managers, to understand the delivery and implementation of the Smile4life intervention at the organisational and NHS Board level and analysed using Grounded Theory methodologies. The findings proposed that NHS Board managers’ main concern was the schisms that they experienced within their organisations, between health and social care, and between general health and oral health. They used the behaviour of hybridising to solve this concern. Two different types of hybridising behaviours emerged from the data: [1] spreading too thin and [2] sharing the load. These behaviours enabled or inhibited the delivery and implementation of the Smile4life intervention.
To understand the variation in Smile4life implementation, found in Studies 1-3, and to identify the specific influences on behaviours, associated with the implementation of this intervention, it was necessary to conduct a quantitative survey with practitioners working in the fields of oral health and homelessness. Doing so would provide important information with regard to recommendations for successful implementation.

Study 4: Therefore a questionnaire was designed, informed by the Theoretical Domains Framework (also part of the BCW). This final quantitative study demonstrated the predictors of reported Smile4life behaviour, highlighting that Smile4life practitioners must have the ability to deliver the intervention, and have positive beliefs and outcomes regarding Smile4life and its role in addressing the oral health needs of people experiencing homelessness.

The theoretically informed conclusions from this research demonstrate the benefits of adopting a range of theoretical approaches within this evaluation. The synthesis of findings from each study allowed for this evaluation to produce recommendations that may be used to improve the future delivery and implementation of the Smile4life intervention. This thesis recommends that:
[1] policy should be developed to support multidisciplinary and multi-sectorial working within oral health, health and social care;
[2] policy makers should acknowledge that the oral health of people experiencing homelessness is a health priority at policy level, not simply a “priority group”;
[3] policy makers should be aware of the organisational and practitioner factors that influence successful delivery and implementation of Smile4life and
[4] Smile4life practitioners should be supported to work within multidisciplinary teams to ensure the successful delivery and implementation of Smile4life.
Date of Award2020
Original languageEnglish
SupervisorRuth Freeman (Supervisor), Andrea Rodriguez (Supervisor), Gerry Humphris (Supervisor) & Isobel Anderson (Supervisor)


  • Dentistry
  • Oral Health
  • Homelessness
  • Qualitative
  • Mixed methods
  • Behaviour change

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