Exploring changes in oral hygiene behaviour in patients with diabetes and periodontal disease: A feasibility study

Abstract Objective Exploring the feasibility to understand changes in oral hygiene behaviour using the Health Action Process Approach (HAPA) model applied to qualitative research interviews in patients with diabetes and periodontitis undergoing standard periodontitis treatment. Methods Patients with type 1/2 diabetes and chronic periodontitis (n = 8) received standard non‐surgical periodontal treatment accompanied with personalized oral hygiene instructions by a dental hygienist. Clinical indices (% bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), % of sites with PD ≥ 5 mm, periodontal epithelial surface area (PESA) and periodontal inflammatory surface area (PISA) were recorded pre‐ and post‐treatment. At 3 months post‐treatment, patients were interviewed using a topic guide relating to oral health. A behaviour change framework was constructed from elements of the HAPA model and used directly to map interview data to evaluate oral hygiene behaviour in these patients. Results Data from this feasibility study suggest a clinical improvement in periodontal status, albeit only monitored for 3 months. Application of the HAPA model highlighted the behavioural change pathway that diabetes patients undertake before, during and after periodontal treatment. The data suggest that patients move through all elements of the motivation phase and all elements of the volition phase except for the recovery self‐efficacy element. Conclusion The novel approach of applying the HAPA model to qualitative research data allowed for the collection of richer data compared to quantitative analysis only. Findings suggest that, in general, patients with periodontitis and diabetes successfully manage to incorporate new oral hygiene behaviours into their daily routine.

given oral hygiene instructions (OHI) as part of their periodontal treatment plan and then typically receive 3-monthly supportive periodontal care (maintenance care) recalls following initial periodontal therapy. 4,5 OHI aims to induce a behaviour change in the patients' daily tooth cleaning regime, such as, for example, introducing the use of interdental brushes or the correct techniques when using a toothbrush. 5 Research into psychological interventions for oral hygiene behaviour is based on a number of behavioural change theory models, such as Health Locus of Control, Social Learning Theory or Theory of Planned Behaviour. 6,7 Originally, behavioural change theory models were applied primarily to improve, for example, uptake of flu vaccinations, cancer screening attendance or to evaluate HIV risk behaviours. 8 However, through continued development and refinement of these models, they have also found wide application in other areas, such as dentistry or diabetes care. 9,10 In primary care dental practice, patients receive OHI from their treating clinician. However, when applying psychological interventions, most research has been conducted with either psychologists or specifically trained dental personnel to provide the intervention. For example, research investigating motivational interviewing as an intervention to improve oral hygiene behaviour was conducted by a clinical psychologist or a trained counsellor. [11][12][13] In addition to using specifically trained dental personnel, other studies have employed frequent visits and group classes with intense supervision of patient compliance to achieve a behavioural change in oral hygiene procedures. [14][15][16][17] It is therefore questionable how representative and feasible such approaches would be for everyday dental practice. Indeed, the most recent Cochrane review on psychological interventions to improve adherence to OHI highlighted that there is a lack of studies with practitioners other than trained specialists facilitating the psychological interventions. 6 To evaluate how successful psychological interventions are in improving adherence to OHI, psychological constructs derived from behavioural change models are matched with clinical or questionnaire data outcomes. For example, psychological constructs such as locus of control, self-efficacy, action-planning or intention are correlated with tooth brushing, plaque index, flossing or questionnaire data in complex pathway analysis regression models. [18][19][20] Specifically, the Health Action Process Approach (HAPA) model 21 is one of the latest behavioural change theories applied to oral hygiene behaviour. 18,20,22 The HAPA model is based on five principles instead of testable assumptions, which makes it distinct from other behavioural change models. 23 The first principle, motivation and volition, is based on a division of the behaviour change process in first developing an intention and then making and acting on a decision. The second principle, two volitional phases, clarifies that the volition phase includes people at different stages of the behaviour change process, namely preintenders, intenders and actors. Principle three is based on postintentional planning, which includes people who are motivated to change but may lack the right skills to do so. Principle four, two kinds of mental simulation, divides the planning phase into two stages. The "when, where and how" of the intended action phase and the coping with barriers to the action phase. The fifth and final principle is phase-specific efficacy. This perceived self-efficacy runs throughout the whole behavioural change process, however, changes in nature from task self-efficacy to maintenance and finally recovery self-efficacy. 23 Whilst the approach to correlate psychological constructs with clinical and questionnaire data results in clear quantitative outcome measures, it does not take patients' emotions and feelings into account and does not identify where patients may be struggling with implementing the required behaviour change. Alternatively, using qualitative research interviews to explore behavioural changes in oral hygiene may provide an overall richer analysis and be especially relevant in a patient group that already has to manage other chronic condition such as diabetes or cardiovascular diseases.
Diabetes and periodontitis are both recognized as chronic inflammatory conditions, linked through immunological changes in inflammatory cytokine networks. 24 This two-way relationship makes patients with diabetes a particularly vulnerable group for developing periodontitis, having a threefold increased risk compared to individuals without diabetes. 25 Patients with diabetes are having to make lifelong changes in their diet and exercise regimes, coping with frequent checks of blood glucose levels and numerous routine medical appointments. 10 Hence, there is a reasonable expectancy that this patient group, in particular, may struggle with fitting in the TA B L E 1 General and clinical characteristics of the study population pre-and post-treatment  Patients were treated in one or two visits, depending on their preferences and clinical needs. Patients were seen by the same dental hygienist (not one of the researchers involved in the study) working at the periodontology referral clinic throughout the whole research.

| Oral hygiene instruction
As part of their periodontal treatment, each patient received personalized OHI from the dental hygienist to motivate them and encourage a high standard of oral hygiene. This advice was based on guidance from the National Institute for Health and Care Excellence (NICE). 27 In brief, patients were given an overview of periodontal risk-factors (eg, diabetes, smoking, family history, specific medications) and were shown pictures to explain the appearance of periodontal health, gingivitis and periodontitis. Patients were asked to use their own toothbrush in front of the dental hygienist holding a mirror and instruction to improve their technique was provided whilst doing so. The OHI was tailored to each patient's clinical needs taking into consideration their demonstrated abilities to use oral hygiene products and the extent and severity of their periodontitis. Patients were provided with interdental brushes with specific instruction into their use (eg, the correct sizing of interdental brushes according to the spacing between teeth).

| Qualitative research interviews and HAPA model application
Research interviews based on a topic guide relating to oral health were conducted at the 3 months review visit prior to the dental hy- Given the constraints of the study and relatively low number of participants, a coding strategy using emerging data saturation analysis was felt unlikely to be achievable and therefore elements of the HAPA model were used directly as a framework to investigate oral hygiene behaviour in diabetes patients 28,29 .The HAPA model comprises two consecutive behavioural phases. The motivation phase in which the psychological constructs "risk perception," "outcome expectations" and the actual "task" of the behaviour all act on the "intention" of behaviour change. This is followed by the volition phase in which the "intention" is transformed into "action." Both phases are dependent on the overarching construct, "self-efficacy" how the action will be carried out, involving self-regulatory skills and strategies. 23 The interviews were coded using elements of the HAPA model constructs as key themes instead of developing themes from the data 28,29 . In the following step, examples for these themes were marked together electronically using NVivo.
Initial mapping of the data against the HAPA constructs was discussed amongst the co-authors for cross-checking of data interpretation and refinement of the analysis. Specifically, the somewhat uncommon approach of not coding for emerging themes was discussed and weaknesses such as the potential of missing out on some important information were acknowledged, bearing in mind that the present study is a feasibility study.

| Statistical analysis
This work is a feasibility study and was not informed by a power calculation. Therefore, a formal statistical analysis was not conducted.

| Ethical approval and sources of funding
Informed written consent was collected from all participants of this study and the study was conducted in accordance with the Declaration of Helsinki. 30 The study was given a favourable ethical

| Qualitative analysis: HAPA model application
Applying the HAPA model to the behavioural change pathway in patients with periodontitis and diabetes can be summarized as shown in Figure 2. Specifically, patients moved through the following phases before, during and after periodontal treatment:

| Intention
The key intention of patients participating in the study was to achieve a consistently high level of good oral health and long-term control of their periodontitis. This is reflected in data illustrating their outcome expectancies, risk perception and task self-efficacy, which come together to act on the intention of improving their oral hygiene.

| Outcome expectancies
Participants were actively seeking a referral to Newcastle Dental Hospital with the view to improve their periodontitis and to over- These outcome expectancies demonstrate the patients' willingness to act on their poor oral health by taking the initiative of asking their dentist for a referral to the dental hospital.

| Risk perception
Suffering from diabetes, participants commonly knew of their in- The perception that diabetes patients had about their risk of developing periodontitis is setting the scene to making changes in their oral self-care.

| Planning: action and coping
Participants indicated that they did not find it difficult to plan their new personalized oral hygiene regime around their diabetes show that patients had the right skills to implement the action of oral self-care within their diabetes management.

| Action
Commonly, participants were able to give a detailed account of their oral hygiene routine:

| Maintenance self-efficacy
Incorporating the personalized oral hygiene techniques into a daily regime was a recurrent finding amongst study participants and they appeared positive and confident: The quotes demonstrate that patients reach self-efficacy in maintaining the OHI to the point of feeling confident about their ability.

| Situational and environmental barriers/ opportunities
Study participants predominantly described bad habits and other illnesses as causes for missing their usual oral hygiene routine:

| Recovery self-efficacy
Study participants did not report to be moving through a "recovery" phase as this was not applicable within the short time-frame of the study.

| D ISCUSS I ON
It is well recognized that adherence to behaviours that optimize oral hygiene are an essential for achieving successful outcomes for periodontal disease treatment. 2 daily interruption, such as shift work, was of little concern. A future study should explore these issues in more detail with the aim to achieve full data saturation in patient interviews.
To the best of our knowledge, the present study evaluates, for the first time, oral hygiene behaviour change specifically in patients with periodontitis and diabetes. Diabetes management itself requires several adjustments by patients such as changes in diet, exercise, frequent checks of blood glucose levels, and routine medical appointments. 10 The expectancy, therefore, was that patients may struggle with the additional task of improving their oral self-care. However, surprisingly, none of the patients reported this to be a point of concern to them. On the contrary, patients stated that due to their complex diabetes management, they were already used to "fitting stuff in" and therefore implementing the new oral hygiene procedures had little impact on their daily routine.
The current study was conducted as a feasibility study and is therefore limited in the conclusions that can be drawn. Notably, the study group was small and future work should consider broadening the recruitment range to take account of influences of socioeconomic and demographic factors, including smoking and body weight, on any behavioural change the patients may undertake. Taking into consideration that, often, the behavioural change is short-lived, 33 a future study should have a longer follow-up period. Also, some patients saw the hygienist twice for their treatment, others only once which potentially may have introduced some form of bias in re-enforcing OHI. Furthermore, patients were recruited from periodontology referral clinics.
This may infer that they already had a higher intention for a behavioural change in their OHI than the average dental patient.
In addition, it would be interesting to repeat interviews over a longer time period to identify whether adherence to the new behaviours changes over time. Future work should also consider a dual approach of applying the HAPA model to both quantitative and qualitative data to identify any results not covered by interview analysis and vice versa.
In summary, through application of the HAPA model to interview data, this study evaluated a novel approach to explore changes in oral hygiene behaviour in patients with diabetes and periodontal disease. Specifically, this approach allowed for the collection of richer data and these preliminary findings suggest that in general, patients with periodontitis and diabetes successfully manage to incorporate new oral hygiene behaviours into their daily routine. It remains to be elucidated if these behavioural changes persist in the longer term and if some of the barriers revealed by the interview data analysis would impact on this.

| Scientific rationale for study
Patients with diabetes undergoing periodontitis treatment have to manage both their oral hygiene and diabetes control. It is not known if there are barriers preventing these patients from implementing a successful oral hygiene routine.

| Principal findings
A routine approach of non-surgical periodontal therapy and personalized oral hygiene instruction (an overview of periodontal risk-factors, tooth brushing instructions and provision of interdental brushes, tailored to each patient's clinical needs) delivered by a dental hygienist are likely sufficient for patients with periodontitis and diabetes to successfully incorporate new oral hygiene behaviours into their daily routine.

| Practical implications
Research into improving oral hygiene behaviour should focus on everyday routine standard dental practice and incorporate more qualitative data to achieve a richer data outcome.