A link work intervention to support dental visiting in people with severe mental health difficulties: The Mouth Matters in Mental Health Effectiveness and Cost-Effectiveness Trial.

Research question: What is the effectiveness and cost-effectiveness of a link-work intervention to support people with severe mental illness to access a routine dental appointment? Background: People with severe mental illness (e.g. bipolar disorder, psychosis) experience extremely poor oral health, compared to the general population, including a greater likelihood of decayed, missing, and filled teeth, gum disease, and dental pain. This can have a profound impact on their quality of life, functioning, and self-esteem. It can add to the already considerable burden of living with severe mental illness. Dentists can prevent and treat oral health problems. However, people with severe mental illness face multiple barriers to attending a dentist, including demotivation, anxiety, and paranoia. This is further hindered by inflexible dental operating procedures and limited access to NHS dentists in the UK. To date, there exist no evidence-based, scalable interventions to address oral health inequalities for people with severe mental illness. Link work interventions attempt to address practical and systemic modifiable barriers to help-seeking that maintain and widen inequities around service utilisation in disadvantaged populations. We recently conducted the first feasibility trial of a link work intervention to support and empower people with severe mental illness to attend a routine dental appointment (NIHR132853). We observed high rates of recruitment, retention, and engagement with the intervention. There was a signal of substantially higher rates of dental attendance and improved oral health related quality of life after nine-months in the intervention arm, compared to treatment as usual. We now want to conduct a full trial. Aims: To evaluate the effectiveness and cost-effectiveness of a link work intervention to facilitate dental attendance in people with severe mental illness. Design: An effectiveness randomised-controlled trial with integrated cost-effectiveness analysis and process evaluation. 480 participants will be recruited from five NHS Trusts and randomised (ratio 1:1) to either treatment as usual or treatment as usual plus the link work intervention. The link work intervention will follow the manual co-developed and used in the feasibility trial. Blind research assistants will support participants to complete assessments at baseline and after nine-months. We will obtain consent to access participant’s dental visiting data via the Business Services Authority. The primary outcomes are i) attendance at a routine dental appointment, and ii) oral health related quality of life. Health economics analysis will assess whether the intervention is cost-effective. A qualitative process evaluation will help to understand how it works and might be implemented. Timelines for delivery: 45 months (1.11.25-31.7.29). This accommodates a 24-month recruitment period (four randomisations per month, per site), nine-month follow-up assessments, and six-month setup and analysis phases. Anticipated impact and dissemination: This research hopes to produce the first evidenced-based intervention for improving the oral health of people with severe mental illness. It could help to overcome inequities in dental access. We have formed a patient and public involvement panel with excellent representation from minoritised groups. They will advise on all aspects of the work, including a dissemination strategy that has reach to groups underserved in research.