The CALM trial: the clinical and cost-effectiveness of a guided self-help cognitive behavioural therapy intervention to reduce dental anxiety in children

Globally, around 13% of children are reported to experience dental anxiety (DA) and its associated negative impacts for the individual, their family and dental team. Children with DA frequently miss dental appointments, even when experiencing symptoms, consequently having poorer oral health and oral health-related quality of life (OHRQoL) than their non-anxious peers. Each year, thousands of children with DA are referred from primary dental care to secondary care to complete treatment. In 2018/19 there were 59,011 paediatric admissions to hospital for dental extractions costing around £50 million. In recent years, a low intensity cognitive behavioural therapy (CBT) based self-help approach has been recommended for management of childhood anxiety disorders. In 2015, NIHR funded the development and feasibility study of a guided self-help CBT resource to reduce DA in children referred to secondary care. The study confirmed key feasibility parameters and when used with 48 children, the guided self-help CBT approach reduced self-reported DA, improved OHRQOL, improved attendance and reduced need for general anaesthesia (GA). The effectiveness of this approach when delivered in primary dental care to reduce children’s DA, now warrants investigation. Aims and objectives The aim is to establish the clinical and cost-effectiveness of a guided self-help CBT intervention to reduce DA in children attending primary dental care settings across the UK, compared to usual care. Objectives are to: conduct an internal pilot trial; determine effects of the intervention on DA, HRQoL, secondary care referrals, attendance and cost-effectiveness; undertake a process evaluation. Study design and timeline This 4-year study is a multi-region, randomised controlled trial involving 600 children (aged 9-16 years) in 30 dental practices. A 12-month internal pilot will assess recruitment rates (of dental practices and participants) and engagement with the intervention, before progressing to the main trial. In each dental practice two dental professionals will take part, one randomly assigned to receive the CBT training and deliver the intervention and the other will deliver usual care. Children with DA attending these practices, in need of treatment, will be randomly allocated to be treated by the CBT dental professional or the control dental professional. Children will complete questionnaires relating to DA, OHRQoL and HRQoL before treatment, just after treatment completion and 12 months post-randomisation. Attendance rates, need for sedation/GA and the costs of the two different approaches will be compared. The primary outcome, DA, will be measured using the Modified Child Dental Anxiety Scale (MCDAS); scores will be compared between groups using a covariance pattern linear mixed model, adjusting for baseline value, other pertinent baseline covariates, time, and an interaction between treatment group and time as fixed effects. A cost-utility analysis will estimate the mean differences in costs and quality-adjusted life years (QALYs), using the CHU9D to generate utilities. Impact and dissemination The study will inform future guidelines, clinical practice and commissioning decisions for the management of children with DA. Findings will be published in high impact, peer-reviewed dental journals and presented at scientific meetings. A trial website with social media accounts will ensure patient and public accessibility to the study’s progress.