# Using realist methods for intervention development to fill a methodological gap: A case study showing the development of an oral hygiene intervention for people with intellectual developmental disabilities

Caoimhin Mac Giolla Phadraig, Koula Asimakopoulou, Denise Faulks, Maria van Harten, Lorraine Ledger, Ann Spencer, Sarah Roux, Ceara Cleary, Blanaid Daly, Catherine Waldron

## ► To cite this version:

Caoimhin Mac Giolla Phadraig, Koula Asimakopoulou, Denise Faulks, Maria van Harten, Lorraine Ledger, et al.. Using realist methods for intervention development to fill a methodological gap: A case study showing the development of an oral hygiene intervention for people with intellectual developmental disabilities. Community Dentistry and Oral Epidemiology, 2023, 51 (6), pp.1130-1140. 10.1111/cdoe.12844. hal-04323742

HAL Id: hal-04323742

https://uca.hal.science/hal-04323742v1

Submitted on 5 Dec 2023

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ORIGINAL ARTICLE

# Using realist methods for intervention development to fill a methodological gap: A case study showing the development of an oral hygiene intervention for people with intellectual developmental disabilities

Caoimhin Mac Giolla Phadraig<fnref n="1" />

Koula Asimakopoulou<fnref n="2" /> ID

<figure><img src="image_3.png" /></figure>

Denise Faulks<fnref n="3" />,<fnref n="4" /> ID

<figure><img src="image_4.png" /></figure>

Maria Van Harten<fnref n="1" />

Lorraine Ledger<fnref n="5" />

Ann Spencer<fnref n="5" />

Sarah Roux<fnref n="6" />

Ceara Cleary<fnref n="6" />

Blanaid Daly<fnref n="1" />

Catherine Waldron<fnref n="1" /> ID

<figure><img src="image_5.png" /></figure>

Correspondence

Caoimhin Mac Giolla Phadraig, School of Dental Science, Trinity College Dublin, Dublin Dental University Hospital, Dublin, Ireland.

Email: macgiolla@dental.tcd.ie

Funding information

Irish Dental Association & Mars Wrigley Foundation Grant; Irish Society of Disability and Oral Health

Abstract

**Background:** Realist methods offer a novel approach to intervention design. Such novelty is needed for effective oral health promotion interventions with people with intellectual developmental disabilities (IDD) and their carers because existing interventions are poorly described and lack theoretical underpinning. In this study, the steps between inception and final intervention development are presented, with an aim to expand understanding of how realist theorizing can be used to develop interventions, and to demonstrate theory-driven intervention development in the field of oral health promotion.

**Methods:** In this intervention development study, the use of realist methods to develop an intervention aiming to improve the oral hygiene of people with IDD is presented. Realist theories (RTs) arising from a mixed synthesis were used to develop the *Keep My Teeth* intervention. The use of realist theory in intervention development was mapped across seven domains and 18 actions with emphasis on how theory informed key actions.

**Results:** Realist theories informed many but not all actions in the development process. Where gaps arose, this was augmented with other systems of intervention development, such as the Behaviour Change Wheel (BCW) and Behaviour Change Technique (BCT) systems. The resulting intervention and underlying theory are presented using TiDieR criteria.

**Conclusions:** It is demonstrated how realist methods could be integrated with substantive theory when developing an intervention. RTs enhanced the contextualization of the intervention that was developed but were insufficient in their own right to guide the development process from conception to intervention. This was overcome by augmenting with substantive theory, in this case, using the BCW and BCT behaviour change systems, to select and specify the behaviours that needed to change. In

<footnote n="1">¹School of Dental Science, Trinity College Dublin, Dublin Dental University Hospital, Dublin, Ireland</footnote>

<footnote n="2">²Faculty of Dentistry Oral & Craniofacial Sciences, King's College London, London, UK</footnote>

<footnote n="3">³Universite Clermont Auvergne, CROC, Clermont-Ferrand, France</footnote>

<footnote n="4">⁴CHU Clermont-Ferrand, Service d'Odontologie, Clermont-Ferrand, France</footnote>

<footnote n="5">⁵St. Michael's House, Dublin, Ireland</footnote>

<footnote n="6">⁶Health Service Executive, Dublin, Ireland</footnote>

<footnote>This is an open access article under the terms of the [Creative Commons Attribution-NonCommercial License](https://creativecommons.org/licenses/by-nc), which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
© 2023 The Authors. *Community Dentistry and Oral Epidemiology* published by John Wiley & Sons Ltd.</footnote>
essence, the BCTs guided which techniques to select, while the RTs guided how to develop and intervene. Robust intervention development in the field of oral health promotion is also presented in this study.

KEYWORDS

behavioral science, dental health education, oral health, oral hygiene

# 1 | INTRODUCTION

In this intervention development study, the use of realist methods to develop an intervention aiming to improve the oral hygiene of people with intellectual developmental disabilities (IDD) is presented. People with IDD experience poor oral outcomes, which contribute to their poor health, further disability and unequal distribution of disease burden.¹ These outcomes arise in large part due to the fact that people with IDD often rely, to varying degrees, on carers to maintain their oral hygiene.² In order to reduce these poor oral outcomes, an intervention was developed to improve oral hygiene with people with developmental disabilities called *Keep My Teeth*.

When interventions are implemented to improve health, emphasis naturally tends to fall on what was done (intervention), and whether this was effective or not (evaluation). While this emphasis may have been undoubtedly useful and clearly understandable, parsimonious views of interventions being effective or not ignore the contexts that explain why interventions actually lead to the outcomes observed. This, of course, is vital to enable interpretation of outcomes and choices around whether to stop, modify or repeat, as indicated. Simply asking 'does intervention x work?' comes at the cost of understanding why an intervention actually works and which contextual conditions are necessary for intervention mechanisms to be activated.³ Methods are thus needed to incorporate such complexity into intervention design and evaluation.

A realist approach is particularly suited to the generation and interpretation of evidence about complex interventions as it uses a different lens to examine why and how an intervention was supposed to work rather than if it worked.⁴⁻⁷ By using a diverse range of evidence, including theoretical and empirical literature and involving key stakeholders in the process, a realist approach increases the clarity and understanding of why an intervention succeeds or not. It aims to identify what it is about interventions that generate change and about the way participants reason and respond to it (i.e., the mechanisms) and under which circumstances the mechanisms are triggered (i.e., the contexts), which result in change (i.e., the outcome). These three elements, context, mechanism and outcome, are presented together as a statement or theory which attempts to answer how, why and what needs to happen for an intervention to work.⁵,⁸

The products of realist reviews are theories, often produced in the form of "if ... then..." statements developed from one or more Context-Mechanism-Outcome Configurations (CMOCs) found in available evidence that outlines the individual or collective responses

to intervention strategies and resources.⁹ Mechanisms can be differentiated into *resource* and *reasoning* mechanisms. Resource mechanisms tend to be more concrete, that is, environmental, organizational or political factors introduced into the context, while reasoning mechanisms are the explanations that people provide at a cognitive level for why they behave differently and are more invisible responses to the context i.e. building trust or confidence. It is the 'interaction' between both resources and reasoning that forms the mechanism. A realist evaluation uses the primary data from an intervention using agreed theories as a working hypothesis to be tested, to see if, why, when and for whom the contexts and mechanisms are at play. The methods adopted here were guided by publication standards and training materials for realist research approaches.¹⁰,¹¹

The realist theories being applied here are based on the findings of a realist review of oral hygiene interventions for people with IDD.¹² A pilot RCT was commenced in February 2020, but the COVID-19 pandemic led to a dramatic change of context, which caused an unexpected cessation and ultimately abandonment of the intervention mid-March 2020. As the intervention was not completed, the scope of this study relates to the intervention as was planned, taking this opportunity to describe the development phase in detail. This adds to the literature on realist methods, theory-informed approaches to oral health promotion, and the emerging literature on intervention development.

Realist methods have a role in all stages of intervention design, implementation and evaluation.¹³ However, whilst there are well-developed standards and guidance documents on how to generate RTs and undertake realist evaluations,¹⁰,¹¹ there is a lack of guidance on how to actually design and develop interventions using RTs. This presents a gap for intervention developers, especially when the RTs themselves may potentially operate at the development phase. This gap mirrors a broader lack of emphasis on sharing intervention development across evaluation and programme planning. The natural focus on implementation and evaluation tends to overshadow the equally important process of actually designing the intervention.¹⁴ That is, why an intervention was undertaken and how was it developed. When given due attention, appropriate focus on development increases the chance of effectiveness within trials and suitable adoption in the real world.¹⁵ This realization has led to an increasing emphasis on reporting, in detail, the design and development phases of how and why interventions are developed.¹⁶

It is thus necessary to focus on the reasons and process of intervention development. So, in this study, the authors aim to expand the understanding of how the products of a realist review, the
theories, can be applied to improve intervention design and devel-
opment with a particular focus on the field of oral health promotion
for people with disabilities.

2 | METHODS

2.1 | Design

An intervention development study design is adopted here, as de-
fined by Hoddinott.¹⁶ Starting with a description of the rationale for
intervening and for including realist methods, the authors then detail
how RTs were incorporated from conception to refinement of the
Keep My Teeth intervention, by mapping these theories to seven do-
mains and 18 actions commonly used in intervention development
(Table 1).¹⁷ Examples of how theories were applied are given. Gaps in
this process are explored before, lastly, describing the intervention
according to TiDier criteria.¹⁸

## 2.2 | Conception (Action 1)

The need for a new intervention was identified when nursing man-
agers within a large IDD residential service provider in Dublin ap-
proached the research team, seeking a single round of oral health
training for staff. However, research has shown that these types of
interventions are often not sustainable.¹⁹⁻²¹ Tentative agreement to
proceed was made, with an initial scoping exercise.

2.3 | Planning (Action 3)

Following a scoping review²² and considering previous endeavours
to implement and evaluate similar interventions,²⁰ it was clear that
contextual factors such as heterogeneity of support needs, insti-
tutional setting, work-place culture, link-in with oral health ser-
vices, social and political factors all added complexity. A Cochrane
review found that interventions were largely ineffective and that
traditional reporting of intervention development was poor.²¹ A
concurrently completed realist review provided details of the in-
tentional and unintentional causal pathways, created by a variety
of contexts and mechanisms, in multiple published interventions.¹²
As realist reviews produce theories to be tested, rather than judge-
ments of relative effectiveness, this review produced six theories
specifically applicable to carer-led oral hygiene programmes for
people with IDD (Table 2). The six RTs from the realist review were
referenced throughout the whole process of intervention devel-
opment, with emphasis on how changes in context may trigger
mechanisms leading to intended or unintended outcomes. Details
on how realist theories were expected to achieve the outcomes
can be found in the original review article¹² and examples of how
RTs were used throughout are provided below.

As all six RTs emphasized the need to plan for sustainability,
every effort was made to include stakeholders who would be instru-
mental in roll out and upscaling if effective. Consequently, members
of the public dental services were sought to join the forming team.
As a first concrete step to develop relationships between people and
institutions, members of the research team, residential service and
public dental service co-designed accessible videos.²³ They were de-
signed to be meaningful, relevant and attractive so trainees would
engage positively and be motivated to provide care (RT2).

2.4 | Planning (Action 2)

At the planning stage (domain of *Planning*), the development team discussed all RTs and felt that RT1 offered particular insight in how to undertake Action 3iii (“Describe and understand the wider context of the target population and the context in which the intervention will be implemented”). RT1 suggests a systems level approach to embedding values across organizations to ensure feasibility and sustainability. Accordingly, the team considered the multiple contexts within which the people who will deliver *and* receive the intervention exist, as part of a wider system. It was clear that any single intervention would have differential effects on contexts of both those delivering and receiving the intervention and would only be effective and sustainable if it fit (and modified) both contexts as a whole. Considering that RT1 identifies systems across organizations as important contextual factors, the team mapped out the differing contexts of each partner institution at a brainstorming session. Potential intended and unintended mechanisms triggered by changes to that context at a systemic and inter-organizational level were discussed and opportunities and threats were explored. This led to a greater understanding of how the intervention may modify context favourably across institutions at a systemic level to achieve the intended outcome and how the context within and between organizations may hamper intervention and roll out.

2.5 | Planning (Actions 4–6)

Having established a focus on both systems-level change and sus-
tainability, it was found that the six RTs did not fully describe the
next steps. For example, while RT2 suggested flexible, practical and
sensitive training, it did not describe the steps needed to achieve
this. In order to progress, development frameworks were reviewed
to identify next steps, settling on a process that aligned closely to ac-
tions four to six of the 18 actions within seven domains of interven-
tion development in the O'Cathain's framework¹⁷ which explores
intervention development and actions typically taken, and the ini-
tial four steps of the Behaviour Change Wheel (BCW), a behaviour
change system covering three phases and eight steps of intervention
development.²⁴
<table><caption>TABLE 1 Map of mixed synthesis process, realist theories and other approaches according to domains and key actions in development.¹⁷</caption><thead><tr><th rowspan="2">Domains</th><th rowspan="2">Action</th><th rowspan="2">Description</th><th colspan="7">Realist Theories</th><th rowspan="2">Comment</th></tr><tr><th>Mixed synthesis process</th><th>1. A systems level approach</th><th>2. Specific and Tailored Training</th><th>3. Carer input and wellbeing</th><th>4. Acknowledge the carers efforts</th><th>5. Setting Goals</th><th>6. Repeat Training</th><th>Other approach</th></tr></thead><tbody><tr><td>Conception</td><td>1</td><td>Identify problem</td><td>X</td><td>X</td><td></td><td>X</td><td></td><td></td><td></td><td>X</td><td></td></tr><tr><td>Planning</td><td>2</td><td>Establish group</td><td>X</td><td>X</td><td></td><td>X</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>3(i)</td><td>Understand context of the potential target population</td><td>X</td><td>X</td><td></td><td>X</td><td></td><td></td><td></td><td></td><td>Realist review aimed to develop theories for how contextual factors trigger mechanisms and impact on outcomes</td></tr><tr><td></td><td>3(ii)</td><td>Assess the causes of the problems</td><td>X</td><td></td><td></td><td>X</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>3(iii)</td><td>Describe wider context</td><td>X</td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td>Realist Review to develop theories; sharing sessions with disability and health service teams</td></tr><tr><td></td><td>3(iv)</td><td>Identify evidence of effectiveness of interventions</td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>Systematic Review</td></tr><tr><td></td><td>3(v)</td><td>Understand wider perspectives</td><td></td><td>X</td><td></td><td>X</td><td></td><td></td><td></td><td></td><td>Realist Review identified potential contexts, mechanism and outcome configurations</td></tr><tr><td></td><td>4</td><td>Specify problem, aims or goals for the intervention.</td><td></td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td>BCW step 1: Define the problem</td></tr><tr><td></td><td>5</td><td>Identify possible changes</td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>BCW step 4: Identifying what needs to change</td></tr><tr><td></td><td>6</td><td>Specify who will change, how and when.</td><td></td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td>Realist review</td></tr><tr><td></td><td>7</td><td>Reduce risk of failure at a later stage</td><td>X</td><td></td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td></td><td>BCW Steps 2&amp;3: Selecting and specifying target behaviour</td></tr><tr><td></td><td>8</td><td>Consider worthwhile continuing?</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>
<table><caption>TABLE 1 (Continued)</caption><thead><tr><th rowspan="2">Domains</th><th rowspan="2">Action</th><th rowspan="2">Description</th><th colspan="8">Realist Theories</th><th rowspan="2">Comment</th></tr><tr><th>Mixed synthesis process</th><th>1. A systems level approach</th><th>2. Specific and Tailored Training</th><th>3. Carer input and wellbeing</th><th>4. Acknowledge the carers efforts</th><th>5. Setting Goals</th><th>6. Repeat Training</th><th>Other approach</th></tr></thead><tbody><tr><td rowspan="4">Designing</td><td>9</td><td>Generate interventions components and features</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>BCTs</td><td>Behaviour Change Technique taxonomy Version 1 (BCTtV1)</td></tr><tr><td>10</td><td>Re-visit wider system in which the intervention will operate</td><td>X</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>11</td><td>Make decisions about content, format and delivery</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td></td><td></td><td></td></tr><tr><td>12</td><td>Design sustainable implementation plan</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td></td><td></td></tr><tr><td rowspan="2">Creating</td><td>13</td><td>Make prototypes</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>14</td><td>Test feasibility and acceptability</td><td></td><td></td><td>X</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">Refining</td><td>15</td><td>Test on a more diverse population</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>16</td><td>Optimize prior to full Realist RCT</td><td></td><td></td><td></td><td>X</td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">Document</td><td>17</td><td>Document the intervention</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>18</td><td>Develop plan for feasibility and full Realist RCT.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

Note: 1 = Identify that there is a problem in need of a new intervention. 2 = Establish a group or set of groups to guide the development process, thinking about engagement of relevant stakeholders such as the public, patients, practitioners and policy makers. 3(i) = Understand the problems or issues to be addressed. Understand the experiences, perspectives and psycho-social context of the potential target population. 3(ii) = Assess the causes of the problems. 3(iii) = Describe and understand the wider context of the target population and the context in which the intervention will be implemented. 3(iv) = Identify evidence of effectiveness of interventions for these problems, or for similar interventions once decisions have been made about the intervention type, so do not reinvent the wheel. 3(v) = Understand wider stakeholders' perspectives of the problems and issues. 4 = Make a decision about the specific problem or problems that an intervention will address, and the aims or goals for the intervention. 5 = Identify possible ways of making changes to address the problems. 6 = Specify who will change, how and when. 7 = Consider real-world issues about cost and delivery of any intervention at this early stage to reduce the risk of implementation failure at a later stage. 8 = Consider whether it is worthwhile continuing with the process of developing an intervention. 9 = Generate ideas about solutions, and components and features of an intervention. 10 = Re-visit decisions about where to intervene. This can involve consideration of the different levels at which to intervene, and the wider system in which the intervention will operate. 11 = Make decisions about the content, format and delivery of the intervention. 12 = Design an implementation plan, thinking about who will adopt the intervention and maintain it. 13 = Make prototypes or mock-ups of the intervention, where relevant. 14 = Test on small samples for feasibility and acceptability and make changes to the intervention if possible. 15 = Test on a more diverse population, moving away from the single setting where early development of the intervention took place and seeking a more diverse sample. 16 = Optimize the intervention for efficiency prior to full Realist RCT. 17 = Document the intervention, describing the intervention so others can use it and offer instructions on how to train practitioners delivering the intervention and on how to implement the intervention. 18 = Develop the objectives of the outcome and process evaluations. This includes determining how outcomes and mediators of change can be measured, developing measures, specifying evaluation design, planning recruitment and considering feasibility of a full Realist RCT.
<table><caption>TABLE 2 Realist theories.</caption><thead><tr><td>Theory</td><td>Refined theories - Context (C) Mechanism (M) Outcome (O)</td></tr></thead><tbody><tr><td>RT1. A systems level approach</td><td>Oral hygiene interventions planned, designed, implemented and sustained at the systems level that ideally establish policy, provide regulation and funding, and monitor staff at all levels to be accountable (C) will embed values across an organization (M) thereby ensuring good quality and sustainable oral hygiene practices are maintained for people with intellectual disability (O).</td></tr><tr><td>RT2. Specific and Tailored Training</td><td>Training that is flexible, practical, sensitive, respectful and inclusive of carers and takes an holistic approach; providing information on health consequences for people with ID, while taking into consideration carers' other duties (C), will be meaningful and attractive to them, increase their levels of self-efficacy, advocacy, positive engagement and motivation (M) to attend training and initiate and sustain delivery of oral hygiene practices for people with an intellectual disability (O).</td></tr><tr><td>RT3. Carer input and wellbeing</td><td>When carers personal attitudes and opinions in relation to providing solutions to challenges, identify relevant topics for training and preference for practical skills training over knowledge, their need for empathy and support and their oral health knowledge, educational level and personal and work environments are considered when planning their training (C), carers will feel supported, encouraged and understood (M), increasing the likelihood of successful training and of them initiating and sustaining delivery of oral hygiene practices for people with intellectual disability (O).</td></tr><tr><td>RT4. Acknowledge the carers efforts</td><td>Sensitively delivered feedback (both positive and negative) at all stages of implementation, evaluation and maintenance of oral hygiene care initiatives and support from others (C) will provide carers with encouragement, incentivization and motivation; improve their levels of self-efficacy and belief in capabilities (M) to continue delivering oral hygiene practices for people with intellectual disability (O).</td></tr><tr><td>RT5. Setting Goals</td><td>Agreed goal setting with achievable steps (C), will provide carers with a reminder of their intention and an incentive (M) to undertake sustained delivery of oral hygiene practices for people with intellectual disability (O).</td></tr><tr><td>RT6. Repeat training</td><td>Regular re-training of staff who are respected/valued within their workplace and who are given ownership of this training to train other staff (C), will reduce knowledge fading, maintain motivation and increase the coping skills, self-efficacy and self-confidence (M) of all staff to sustain delivery of oral hygiene practices for people with intellectual disability (O).</td></tr></tbody></table>

### 2.5.1 | Selecting and specifying target behaviour

Next, the specific problem was stated: that oral hygiene behaviours, such as tooth brushing, were not carried out effectively or regularly by / with professional carers in residential care units. Recognizing the complexity of care needs across people with IDD, focus was given to the two inter-dependent carer-led behaviours essential for sustainable and flexible personalized care: *mouth care planning* and *mouth care (with prioritization of tooth brushing)*. Specifically, the aim was to modify carer capability, opportunity and motivation to plan and deliver mouthcare within an agreed time frame.

### 2.5.2 | Identifying ways of making changes

To understand the barriers and facilitators to change, the team considered the RTs and, with those theories in mind, interviewed nursing and social care staff across the IDD service and managers in similar organizations to explore their implications. It became clear that mouth-care plans were not undertaken meaningfully, consistently, or in many instances, at all. Staff had received no training regarding mouthcare planning in almost a decade. Oral care was reportedly not a priority for some staff and barriers abounded.

### 2.6 | Designing (Actions 9-12)

To design intervention components, the team cross-referenced the RTs with accepted Behaviour Change Techniques listed in the Behaviour Change Technique Taxonomy (BCTvT1). Each candidate BCT was screened according to the RTs, considering whether the contexts and resource mechanisms were present and whether the defined reasoning mechanisms were likely to be triggered by candidate BCTs. In this way, the RTs guided BCT selection. Once a BCT was identified as having potential, the team explored how it could best be delivered, with emphasis on RTs two to five. For example, when selecting the BCT *Information about consequences*, RT2 mandated that training be attractive to carers, and tailored to their educational needs, focused on practical skills and delivered in a flexible format to suit staff rotas. RTs informed both steps at this stage; for example, when selecting BCTs, RT5 (Setting Goals) strongly supported the inclusion of the BCT “Goal setting”, because the realist theory stated that agreed goals that specify what the carers were expected to achieve would provide carers with a reminder of their intentions and an incentive to sustain them. RT3 and RT4 guided the team in how the intervention should be designed to optimize the context: stating that carers needed to be and feel supported, have their efforts acknowledged, and have their opinions and ideas included in the intervention design, development and training.
Practical issues were also courted at this point from all stakeholders and consensus took shape- for example, the timing and scheduling of the intervention was guided by feedback and the RTs. The training needs of trainers and other scale up issues were also considered, and the intervention refined accordingly.

## 2.7 | Creation, refinement, documentation and evaluation planning (Table 1, Actions 13–18).

Training format, length, tone and aesthetic were shaped considering features of RTs two to four that respectful and inclusive training will be attractive and meaningful for carers and that personal work environments must be considered.

A pilot Realist RCT was designed to refine the intervention and to identify the effectiveness of two slightly different interventions to determine the most cost effective one to scale up. A realist evaluation framework was developed to test the theoretical domains and identify mediators and moderators effecting the changes in behaviour achieved.¹⁰ Implementation began with participant recruitment and baseline data collection for a pilot study in February 2020; however, the COVID-19 pandemic led to a dramatic change of context, which made post-measurement impossible, ultimately leading to abandonment of the pilot study mid-March 2020. The results given here consequently relate to the intervention as planned but without evaluation.

# 3 | RESULTS

## 3.1 | Brief Name

The Intervention is named *Keep My Teeth*. This name was chosen by residents and carers in the residential setting where this intervention was developed, promoting the importance of oral hygiene for clinical outcomes over the life course for people with IDD.

## 3.2 | Theoretical basis and programme logic

*Keep My Teeth* is a carer training programme involving four steps, which are based on eight BCTs and six RTs. The final programme theory is described in Table 3.

Step One *Training*: Training should enable support staff to plan and deliver mouthcare to dependent persons by delivering information about health consequences, instruction, demonstration and practice (BCT 4.1, 5.1, 6.1 & 8.1). Training should be short, practical and flexible so as to consider carers' broader responsibilities, and be repeatable (RT2 & RT6).

Step Two *Mouth care planning*: Trained carers should produce a mouth care plan for whom they care. These plans should comprise achievable steps to achieve goals (RT5) and action planning (BCT 1.1 & 1.4).

Step Three *Mouth care*: The action plan should then trigger the behaviours of mouth care as per the Mouth care plan among staff who have the capability to do so (activated through training).

Step Four *Feedback and support*: The intervention provider (e.g. a trained dental hygienist) should provide intensive assistance through feedback and practical social support for the duration of the programme (BCT 2.2 & 3.2), tapering once goals are approximated. This support would be sensitively and empathetically delivered by a purposely embedded, trained professional (RT4 & RT3). This step will only be provided to half of the carers, as part of the Realist RCT to evaluate the effectiveness and need for this level of support.

**Outputs and outcomes:** These steps will confirm, refute or suggest refinements to the RTs, and should lead, proximally, to a change in behaviours of planning and delivery of mouthcare, leading to effective plaque removal thereby preventing periodontitis (and caries), distally maintaining oral health, function and oral health related quality of life.

## 3.3 | Programme Steps

Step One. Training should involve digital materials including an interactive training presentation (File S1), presented using a laptop and monitor. This presentation includes four short videos. One video presents the benefits of oral health, another provides an overview of oral care planning. A third and fourth video demonstrate the physical act of tooth brushing for people with disabilities with different levels of support and different toothbrush designs. These and further videos are available at www.brushmyteeth.ie, an inclusive resource developed as part of this intervention. Physically, training adopts active learning through use of an evidence-based workbook (File S2). Special brushes, clinical waste bags and PPE are used for the practical element of training. Step Two is undertaken with printed Mouthcare plans (File S3) in tandem with the person for whom care is planned and Step Three is undertaken using the type of toothbrush that has been selected for the individual. Step Four is facilitated using the mouthcare plans and bespoke brushing records.

## 3.4 | Procedure

*Keep my teeth* is a four-step intervention lasting up to 8 weeks and must be undertaken with agreement at service level.

Step 1: Firstly, an initial face-to-face training session should be delivered including didactic and practical training. Before training, staff and managers should be consulted to find a time that considers carers' other duties. For Step One training and pre-test survey, 90-120 min should be set aside. Training should open with an overview and paired discussion about the benefits of mouthcare. A summary video on benefits of mouthcare are then shown. Next barriers should be explored in pairs and fed back to the group. Solutions should be introduced. Next, videos summarize how to develop a mouthcare plan and how to brush teeth for a range of care needs
<table><caption>TABLE 3 Theoretical framework for Keep My Teeth.</caption><thead><tr><th colspan="4">Theoretical basis</th></tr><tr><th>Step</th><th>BCT</th><th>RT</th><th>Mode of delivery</th><th>Personnel</th><th>Materials</th></tr></thead><tbody><tr><td>1. Training</td><td>5.1 Information about health consequences<br>4.1 Instruction on how to perform a behaviour<br>6.1 Demonstration of behaviour<br>8.1 Behavioural practice/rehearsal</td><td>RT2 Specific and Tailored Training:<br>RT6 Repeat training</td><td>Face to face<br>Active learning<br>Participatory<br>Didactic learning through activities, powerpoint and videos<br>Practice using special toothbrushes</td><td>To support staff<br>By dental hygienist</td><td>Powerpoint<br>Laptop and screen<br>Workbook,<br>Mouthcare plan<br>Special brushes<br>Clinical waste bags<br>PPE</td></tr><tr><td>2. Mouthcare Planning</td><td>1.1 Goal setting (behaviour)<br>1.4 Action planning</td><td>RT5 Achieving Goals</td><td>Face to face<br>Active learning<br>Participatory<br>Practice using template mouthcare plans</td><td>By trained support staff<br>With dental hygienist</td><td>Mouthcare plans</td></tr><tr><td>3. Mouthcare</td><td>NA</td><td>NA</td><td>Tapered observation of tooth-brushing and practical support provided</td><td>By trained support staff</td><td>Special Tooth brushes</td></tr><tr><td>4. Feedback and support</td><td>2.2 Feedback on behaviour<br>3.2 Social Support (Practical)</td><td>RT4 Acknowledge the carers efforts<br>RT3 Carer input and wellbeing</td><td>Tapered observation of tooth-brushing and practical support provided</td><td>By trained Dental Hygienist with support staff</td><td>Recording sheets</td></tr></tbody></table>

Abbreviations: BCT, Behaviour Change Technique; RT, Realist Theory.
using a range of toothbrushes. Following this, staff are invited to brush each other's teeth using a special toothbrush (Superbrush) and give feedback. This helps staff empathize, feeling what it is like to have someone brush their teeth. To end Step One, staff are shown how to document mouth care and agree a plan for tapered intensive support from the provider.

At Step Two, the intervention provider should support trainees to complete a mouth care plan for all service users and finalize all mouth care plans within 1 week of the training session. Step Three involves trainees enacting planned mouth care behaviours with residents on a routine basis within residential units and is not observed by the intervention provider. Step Four lasts up to 8 weeks, and involves on-site support and feedback to the trainees in a tapered fashion. The provider should attend the residence to check in on any issues in relation to the mouthcare plan and mouthcare as often as needed: at first intensively, tapering as goals are achieved. To end the intervention, carers must complete a post-test evaluation survey and nominate a local champion to co-ordinate post evaluation implementation.

## 3.5 | Provider details

Keep My Teeth should be delivered by a single provider, who is a suitably qualified oral health professional, such as a dental hygienist, a dental nurse or oral health promoter. Much of the content delivery is automated through videos, which makes the intervention reliably deliverable by a range of trainers. Training of the trainers is achievable within a day and is designed to be scalable across public dental services. The training videos can be re-watched by the trainees at any time.

## 4 | DISCUSSION

In this intervention development study, the authors primarily aimed to explore how realist methods can be used to develop an intervention in the field of oral health promotion and secondarily to report the development of an intervention.

The process of developing an intervention is shared, using RTs arising from a realist review, as part of a mixed synthesis. This synthesis produced six RTs, which were instrumental to the development of the intervention. The RTs allowed for a consistent focus on context and mechanisms throughout development. However, they did not prescribe the development process. This meant that processes and techniques from intervention development systems were applied when needed. The Behaviour Change Wheel was adopted as a comprehensive, evidence-based system to fill gaps such as selecting and specifying behaviours and behaviour change techniques.²⁴ The use of RTs was mapped to O'Cathain's framework,¹¹ revealing where the synthetic process, RTs and other systems were used across actions and domains of intervention development. This offered a novel perspective on the use of realist theories in intervention development.

The mixed synthesis guided the planning and designing stages well, while the BCW guided the specification of target behaviours and identification of what needs to be in place to support behaviour change. The RTs enhanced the selection of intervention components and their construction, but the Behaviour Change Techniques (BCTs) as listed in the Behaviour Change Technique Taxonomy (BCTtV1) were still essential, particularly in the later design domain.²⁵ In essence, the BCTs guided what technique to select, while the RTs guided on how to develop the intervention.

To reflect critically on the use of realist methods here, a number of strengths and weaknesses arise. Firstly, the review was limited to focus on the needs of the carer rather than on the needs of the people with IDD. The limitations of the realist theory generation process applied here are discussed elsewhere.¹² Regarding the use of RTs, it was found that realist methods and theories were helpful in guiding day-to-day decisions. For example, they led to an extended and in-depth preparatory phase of theorizing and coalition development; encouraged the adoption of multiple perspectives; systems thinking, and focus on context and mechanism. The selected RTs highlighted the importance of considering the complex interpersonal, institutional and individual contexts of carers, people with disabilities and dental services when designing. The RTs also highlighted how early in the process of intervention development it is necessary to focus on context in the hope of long-term sustainability. Particular emphasis can be given to focusing on feasibility and sustainability at a systems level, across stakeholders, from an early stage.

On the other hand, the use of realist theory alone was insufficient to develop an intervention. The RTs framed how the contexts and mechanisms might interact during intervention development, implementation and beyond, but some RTs lacked prescription, leaving the BCW to guide their application. There was overlap, particularly between RTs two to five and selected BCTs. In essence, the RTs guided how the intervention should work, rather than what should be done. By combining both approaches pragmatically, an emphasis on context and human agency was achieved.

The implication of these findings is that there is a lack of guidance on how to handle RTs at this stage of interventional development. While there are many traditional frameworks to aid design, this is a gap in the realist literature. While there is clear guidance on how to develop theories and how to evaluate them in practice such as RAMESES and RAMESES II,¹⁰,¹¹ and there are numerous examples of realist interventions and evaluations, there is little published to guide intervention developers in applying RTs when actually designing the intervention. The recently published MEMORABLE realist synthesis is the first seen by the authors to consider this gap.²⁶ The MEMORABLE team also used an existing substantive theory, normalization process theory, to guide further analysis and use of the realist data and outlined the processes that led them to their choice of substantive theory.

Based on the above the following recommendations can be made. Firstly, RTs can be pragmatically combined with intervention development systems to offer an excellent opportunity to develop contextually sound interventions. Secondly, realist
reviewers should consider the CMO configurations that may op-
erate from conception, planning, as much as during the design,
creation refinement and intervention stages, when generating
theories to inform interventions. Thirdly, the theories used here
were developed for a relatively specific population; however, RTs
are intended to function at the mid-range level, so these theories
may be transferable to other settings if the same contexts and
mechanisms are in operation. Lastly, it is important for researchers
to note, that when using RTs developed from a realist review, they
may require the support of a domain specific substantive theory
to develop the intervention. Future intervention developers, who
apply RTs in the design of their intervention, should outline the
decision processes that occurred when filling any gaps.

The second aim in this study was also achieved by offering a
detailed description of the development, programme theory and
procedures of the *Keep My Teeth* intervention itself. This addresses
a lack of descriptive and theoretical detail in the literature of inter-
vention development, which gives insight into whether or not to
repeat or modify successes and avoid failure in this field and more
generally.²⁴ The detail and resources shared here may be useful in
development and contextualization of future interventions and re-
duce development time and costs.¹,²⁰ There are few comparable oral
health extended descriptions of intervention development apart
from one, which adopted a PRECEED-PROCEED framework to ul-
timately include training, demonstration and support from a dental
hygienist.²⁷ Interestingly, this converges on the design arrived at
here, through separate methods.

5 | CONCLUSION

This study showed how realist methods can be used to develop an
oral health intervention. RTs enhanced the contextualization of the
intervention developed but were insufficient in their own right to
guide the development process from conception to intervention.
This was overcome by augmenting with substantive theories, in this
case, from the Behaviour Change Wheel behaviour change system,
to select and specify behaviours and behaviour change techniques.
In essence, BCTs guided what technique to select, while RTs guided
how to intervene. Based on these experiences, the process of realist
intervention development should include a focus on the interven-
tion development phase when theorizing. In this study, robust inter-
vention development in the field of oral health promotion for people
with disabilities is also demonstrated.

AUTHOR CONTRIBUTIONS

Conceptualization, CMGP, CW, SR, CC, LL, AS; methodology, CMGP, CW, SR, CC, LL, AS, KA, DF; analysis, CMGP, CW, KA, DF, BD; data curation, CW and CMGP; writing—original draft preparation, CMGP and CW; writing—review and editing, CMGP, CW, SR, CC, LL, AS, KA; visualization, CW and CMGP; supervision CMGP and CW. All authors have read and agreed to the published version of the manuscript.

FUNDING INFORMATION

Funding was received to develop the resources used in Keep My
Teeth from: Irish Dental Association & Mars Wrigley Foundation
Grant and Irish Society of Disability and Oral Health.

ACKNOWLEDGEMENT

Open access funding provided by IRel.

CONFLICT OF INTEREST STATEMENT

The authors have no conflicts of interest to declare.

DATA AVAILABILITY STATEMENT

Data sharing is not applicable to this article as no new data were cre-
ated or analysed in this study.

ORCID

Koula Asimakopoulou https://orcid.org/0000-0003-3420-8523

Denise Faulks https://orcid.org/0000-0002-1191-5658

Catherine Waldron https://orcid.org/0000-0002-0408-8543

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## SUPPORTING INFORMATION

Additional supporting information can be found online in the Supporting Information section at the end of this article.

**How to cite this article:** Mac Giolla Phadraig C, Asimakopoulou K, Faulks D, et al. Using realist methods for intervention development to fill a methodological gap: A case study showing the development of an oral hygiene intervention for people with intellectual developmental disabilities. *Community Dent Oral Epidemiol*. 2023;51:1130-1140. doi:10.1111/cdoe.12844