Title: Development of a preference based child-centred measure of dental caries suitable for use in economic evaluation
Funder: Department of Health and Social Care

Abstract: Title Development of a preference based child-centred measure of dental caries suitable for use in economic evaluation The problemDental caries is a prevalent oral disease amongst children and can cause chronic pain, local infection and in some cases may lead to emergency hospitalisation due to spread of the infection and systemic illness. Approximately 45,000 children aged up to 16-years were admitted to hospital in 2013-2014 with a diagnosis of dental caries, making it the most common reason for children to require admission. In the UK, the estimated cost of treatment for children under 18-years of age requiring extractions under general anaesthesia (GA) in 2013-2014 was 37 million. Dental caries is a largely preventable disease, thus there are a range of different programmes available to reduce the incidence in children. However, there have been few economic evaluations to determine the cost-effectiveness of such programmes. Within paediatric dentistry, this scarcity of economic evaluations could be attributed to the lack of a suitable instrument to measure Quality Adjusted Life Years (QALYs). Development of a validated utility measure, specifically for children is both recommended and potentially achievable through the adaptation of a novel child-centred caries-specific oral health-related quality of life measure, CARIES-QC. Ordinal methods, such as Discreet Choice Experiments (DCE) and Best Worst Scaling (BWS), have shown promise for use in utility measures with children; however, there is little evidence to identify the most appropriate method to use.Aim To develop a preference-based measure of dental caries based on the preferences of children and young people.PlanA systematic review of use of health state valuation techniques in children in the literature will be undertaken initially, as findings may further inform the proposed study.Next, CARIES-QC will be refined to make it amenable for health state valuation, whilst minimising loss of descriptive information. A two-stage approach will be adopted to achieve this, utilising both Rasch analysis and discussions with children and young people. A final descriptive system will then be constructed, combining both DCE and BWS tasks, and converting them into a computerised survey. This will then be piloted with five secondary school children to help formulate a topic guide. Think aloud' one-to-one qualitative interviews will then be conducted with a purposive sample of approximately 30 secondary school children in South Yorkshire aged 11-16 years, as they complete the survey. The interviews aim to identify which tasks children of each age group can successfully manage, how many tasks they can complete and which type of task they prefer. Interviews will be recorded and transcribed verbatim. Field notes will be taken throughout, focusing on how much help the child required from the interviewer whilst completing the survey. Framework analysis will employed to analyse the data and this will inform the next stage of the project. The survey will be adjusted to include only the preferred type and number of tasks, with the addition of some basic socio-demographic questions. The modified survey will then be issued to 500 children around the UK for valuation, excluding age groups deemed unable to complete the survey online independently. Appropriate regression modelling techniques will be applied to predict health state values for each health state defined by the descriptive system. The results will need rescaling onto the 0-1 (dead-full health) QALY scale, hence interviews with 25 locally-recruited adolescents/young adults will be carried out using cardinal techniques. The rescaled algorithm will then be able to give a preference weight for each health state defined by the descriptive system, which will enable calculation of QALYs. The findings will be disseminated and the utility measure made available for future research.

Lay abstract: Title Development of a questionnaire with children about rotten teeth (tooth decay) that is suitable for use to test the benefits of different types of treatment. The Problem Tooth decay is a common disease worldwide. A national survey found that nearly half of 8-year-olds had decay in their baby teeth and the same percentage of 15-year-olds had decay in their adult teeth. Dental decay can cause children to have toothache, problems sleeping, eating, speaking and having to take time off school. Dental decay is the most common reason for children to be admitted to hospital, and costs the NHS around 3.4 billion each year. The NHS has a limited amount of money and demand for services is going up. Decision-makers have to choose which treatments to fund, considering whether they are value for money (cost-effective). This means the costs and benefits are compared. In dentistry, there is no measure that can be used to work out and compare the effectiveness of treatments for children's teeth. This means decisions about funding of dental services for children with tooth decay are not well informed. A questionnaire that can work out the effectiveness of treatments and is suitable for children to complete themselves is needed. Seeking children's opinions tells us which aspects of tooth decay matter to children most, so that treatment decisions relate to what is actually important to them. Aims I plan to adapt a questionnaire called CARIES-QC with children's input, to make it suitable to test the benefits of dental treatment. The questionnaire will be made up of two different types of activities, or tasks, for children to complete to see how they would rate different parts of dental decay. I also aim to find out which type of task is most suitable, how many tasks children can manage and which age range of children can complete them. I will also investigate whether children can complete these tasks alone on a computer. Project Plan Firstly, I will look at research already carried out to find out which similar tasks have been used with children before, and what ages can manage such tasks. There are different types of tasks available but researchers do not know which children find the easiest to understand. Next, I will study if I can reduce the number of questions asked in CARIES-QC and it still be a useful tool. I will work closely with a group of young people (Young People Panel) during this stage.This will allow me to design an online questionnaire based on my new version of CARIES-QC. The panel will be asked to try the questionnaire to check they understand it. I will then ask 5 children from secondary schools to try completing the online questionnaire. I will ask them some questions and encourage them to 'think aloud'. This will help me to identify some important questions that I can use as a guide for further interviews. Next, around 30 children aged 11-16 years from secondary schools in South Yorkshire will be asked to complete the online questionnaire. I will be there to provide help if needed, and will ask the children some questions, encouraging them to think aloud' and talk through their decisions. This will help me to identify which style of task children prefer, how many tasks they can manage, which age groups can really understand the questions, and which age groups can manage to complete it online alone. The Young People Panel will be involved in addressing any issues that arise. I will then change the online questionnaire so that it only contains the children's preferred type of tasks, and a number of tasks that children are able to complete. Finally, the questionnaire will be given to 500 children around the UK, using only the age groups that I know will be able to manage to complete it alone. I will then analyse the results, and carry out a process called 'modelling'. A questionnaire like this can produce many potential results, and we need all the results before it can be used to measure benefits. As it is not possible to ask so many children to complete the questionnaire, the modelling process estimates the other potential results. The new measure, suitable for measuring the benefits of dental health, will be made available from the website and can be used in future research. I will share the results with everyone involved, the general public, other healthcare professionals and decision-makers, via a website, posters, reports and presentations at public events and conferences.

Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING
Health categories: ORAL AND GASTROINTESTINAL