V., concesionarias de las emisoras identificadas con las siglas XEAD-AM 1150,

A key aim in theory-based evaluation is to establish what are the mechanisms, or ‘active ingredients’ by which an intervention works (Michie et al., 2005). This aids both the understanding of causal chains within the intervention and the translation of interventions across contexts. Within Childsmile, it is therefore essential to develop a sound understanding of how particular features of the DHSW intervention lead to intended outcomes, in order for the processes to be improved and the intervention optimised.

Medical Research Council (MRC) guidance strongly recommends that, in the development stages of an intervention, the processes by which the intervention components are thought to bring about the desired outcome (according to evidence or expert opinion) should be mapped (Craig et al., 2008). One method

that can be used to map the components and processes involves creating a ‘logic model’.

A logic model is “a pictorial representation of the theory of how a programme works” (Hawe, 2015). Figure 1.3 shows an extract from the Childsmile

programme logic model, which shows those aspects of the model that relate to the DHSW intervention.

It can be seen from Figure 1.3 that the theorised long-term outcomes of the programme include: reducing dental decay in all children in Scotland; reducing oral health inequalities; improving oral health and oral health-related quality of life in children; reducing the need for reactive dental care; increasing cost- effectiveness of oral health activity; and, improving oral health behaviours and oral health in the general population. In order to achieve these long-term outcomes, it has been theorised that certain planned activities will lead to certain outputs which will, in turn, bring about short-term and interim outcomes.

This map of processes and outcomes aids evaluation, as vulnerable points in the causal chain can be identified (Moore et al., 2015). At the time of first

implementation of Childsmile Practice, it was known that certain activities would be carried out and it was hoped that these activities would lead to the various outcomes. However, little was known about the processes, mechanisms, or ‘active ingredients’ necessary for each link in the chain to operate

effectively. For example, how health visitors should identify children in need of Dental Health Support Worker (DHSW) intervention or what that intervention should involve in order to achieve a greater percentage of children registering and attending primary care dental services.

The Childsmile programme can be said to be a ‘complex intervention’; however, the DHSW intervention could be referred to as a complex intervention in its own right as there are a number of behaviours required of those delivering and receiving the intervention; there are a number of various intended outcomes; and a degree of tailoring is required (Craig et al., 2008).

Figure 1.3- E

xtract from the Ch

ildsmile Practice logic model, a

s record

ed in Nov

One aspect of conducting a theory-based evaluation on a complex intervention is the need to attend to the issue of unintended variation. In large-scale

implementation of interventions, variation is almost inevitable. One of the challenges for implementing complex interventions, such as the DHSW

intervention, is in achieving the implementation of an ‘adaptive’ intervention that is effective.

An adaptive intervention is one that is permitted a degree of variation in

domains such as the addition, deletion or modification of components (Perez et al., 2016). Such adaptations affect the fidelity of the intervention to the

proposed model; however, this does not necessarily undermine the programme effectiveness, and may even enhance it. Therefore, it is not only important to understand the links in the causal chain of the logic model but also what level and type of variation is necessary for the intervention to be effective and what may be counter-productive (Moore et al., 2015).

1.6.2.1 Explicating the DHSW intervention

As a complex intervention is rolled-out, it is recommended that an ongoing process evaluation be undertaken (Moore et al., 2015). A process evaluation records any incongruence between the design and the implementation of an intervention. This is essential information as, if the intervention were to be shown to be ineffective, process evaluation data can shed light on whether the intervention design was inherently flawed or if the lack of success was possibly due to partial implementation.

Process evaluation of the Childsmile programme is conducted continuously. Quantitative and qualitative process evaluation reports are published at regular intervals. The findings show that there is considerable variation in how the DHSW intervention has been implemented across Scotland (Childsmile Process Evaluation Reports, 2010-2015; Childsmile- National Headline data, 2011-2015).

One example of such variation is the type of team within which a DHSW may be placed. This may either be within a Public Health Nursing Team or a Dental Services Team. There is variation in other aspects of the implementation of the role in each Health Board and even at the Community Health Partnership (CHP)

level. As the integrated Childsmile programme was rolled out across Scotland, health boards adapted the DHSW role to allow for factors such as the

characteristics of the health boards (e.g. rural or urban), the organisational structures, available resources and pre-existing roles and responsibilities.

Another challenge to the implementation of the DHSW role, reported by Deas et al. (2013) is that, although key actors in the development of Childsmile were supportive of the planned community development approach, they have

acknowledged that there was a lack of evidence to support it. Key stakeholders also did not hold a joint vision of what ‘community development’ should mean for the DHSW role. In some cases, those employed as DHSWs were over-qualified and did not come from the targeted communities; therefore, the ‘peerness’ of the DHSW role was lost. This was, in part, a consequence of recruitment for the role being subjected to NHS recruitment processes, which require vacancies to be offered those displaced from NHS posts.

Central to the programme of research reported in this thesis are the concepts of targeting the right children and tailoring an intervention to meet individual families’ needs. Neither of these concepts had been adequately explicated when the programme had been implemented and much of the detail on how to

‘target’ and ‘tailor’ was left open to interpretation by those implementing the DHSW intervention ‘on the ground’.

Childsmile monitoring data had shown that there was variation across Scotland in the degree to which health visitors were engaging with the pathway for referring targeted individuals for DHSW intervention. Furthermore, there was a lack of clear consensus in the Childsmile literature on the characteristics of ‘the right children’.

Throughout data collection for the process evaluation, when asking those implementing the programme ‘on the ground’ how aspects of the intervention were being delivered, Childsmile researchers repeatedly came across the phrase “it’s tailored to individual families’ needs”. It was unclear, however, what specific strategies or actions were involved in ‘tailoring’ the intervention to individual families’ needs, how the implementation of this undefined concept

varied across Scotland and, indeed, how this ‘tailoring’ should be carried out in order to be effective.

After Childsmile Practice was rolled out across Scotland, it was known that there was variation in the implementation of the DHSW intervention (Eaves & Gnich, 2013). A key question is what effect this variation had on targeting the right children and tailoring to their needs. It was important to explore whether this variation was adaptive or if it was diluting the effectiveness of the intervention. Ultimately, it was clear that the DHSW intervention needed further development before it underwent summative evaluation. In order to optimise the

intervention, it was necessary to explore how it was being implemented, how it

should be implemented, and what the impact of the intervention on dental

participation was at the early phase of implementation.

This thesis takes a mixed methods approach to evaluation. The implementation of mixed methods was carried out from a pragmatic stance. Therefore, data collection methods were chosen based on their ability to answer each research question and, in analysis and interpretation, convergence between data sources was used as an indication of the reliability of the results (Davies, et al., 2003). Each results chapter in this thesis relates to a particular research question, with qualitative and quantitative data presented together in each chapter where appropriate. Key results are provided in the summaries at the end of each results chapter. Key emerging themes are discussed in the context of the wider literature in the final chapter.

2 Aims and objectives