Investigating socioeconomic inequalities in oral health using the Adult Dental Health Survey

An overview of the dental conditions of the British population suggests that the best oral health is enjoyed by those towards the top of the social scale, while the worst oral health afflicts those towards the bottom. This project aims to measure the unequal distribution of good oral health across the population, to investigate why it is unequal, and to establish whether it is getting more or less unequal over time. This is an important time in the development of dental services and the findings will feed directly into the development of health policy in the UK and inform international efforts to reduce inequalities in oral health.

It is understandable that not everyone enjoys the same level of health, because of the ageing process, gender differences and different genetic endowments. However, when people are in need of care, there are over-arching equity considerations. These determine that individuals with different levels of need are treated differently in order to meet their needs (vertical equity), while those with the same level of need are treated the same (horizontal equity).

The problem for policy makers and practitioners are the health inequalities that are potentially avoidable and unjust, specifically those that are related to wealth, education or social position. These reflect wider inequalities in life's opportunities, in turn preventing people from maximising their own potential, affecting the wider economy and society as a whole.

Oral health is a key element of health overall, and those suffering from poor oral health face considerable social and financial burdens. The impact on a person's employment opportunities from having (for example) unattractive teeth as a young adult, or social opportunities because of poorly-fitting dentures later in life, are easy to see. Further, the costs of improving oral health can spiral, even within a national health system. Expenditure on oral health reaches over £5Bn annually in England alone (NHS and private), yet it is an area which has been largely overlooked in the inequalities literature. In this study we investigate the issues surrounding oral health inequalities through the analysis of a unique secondary dataset - the UK Adult Dental Health Survey. This has been run five times, roughly every decade from 1968 to 2009, and in this study we will use the 1988, 1998 and 2009 data.

This project will investigate four issues. Firstly, it is important to measure the level of socioeconomic inequalities and to know what aspect of oral health to measure. Using statistical methods applied to a range of oral health outcomes and socioeconomic indicators, we will identify a broad range of oral health inequality measures, revealing the differences between inequalities in clinical measures (e.g. the number of teeth) and how people report their own health (e.g. oral health related quality of life). This is a time of great change in dental services, so these will provide benchmarks against which policy interventions can be assessed. Secondly, this project will investigate the interactions and influences of a range of indicators of social position and wealth on oral health. These are often complex and unless they are understood it is difficult to develop policies to improve health for everyone, but understanding them means that it is possible to intervene to improve health. Thirdly, the project will investigate how these myriad social and economic influences lead to inequalities. This means that any intervention or policy change intended to improve health, improves health for those who most need it. The final element will be to look at the time trend of oral health inequality, comparing recent data (2009) with data from the decades previously (1988 and 1998). This is a unique possibility with the data we have and will give a richer understanding of how the world of oral health is changing and how urgent any intervention may be.

This project will contribute significantly to the understanding of socioeconomic oral health inequalities in the UK. We anticipate national and international impacts for researchers and practitioners. Impacts will be delivered through workshops, seminars, conferences, publications, and digital and traditional media. These are described in the Pathways to Impact.

Who will benefit?
The applicants are multidisciplinary and highly skilled, and the project is relevant to researchers, nationally and internationally, from a wide range of disciplines. There will be direct and indirect beneficiaries of this research. Directly, the outcomes will benefit academics in the areas of social science, economics, social epidemiology, public health and clinical dental research, where research on oral health inequalities will fill an important gap in the inequalities literature. Indirectly, this will stimulate further research into oral health inequalities.
The most important reason for researching inequalities is to aid the formulation of interventions to reduce inequality, with direct public benefits. It will benefit policy makers, and through evidence-based policy, it will benefit patients and the public. With the importance of oral health inequalities increasingly acknowledged, and the experience of the project team in communicating with and guiding decision makers, the transition to benefit is clear. Internationally it will benefit the International Association for Dental Research and the World Health Organization through their research programmes on oral health inequalities. It will benefit practitioners and patients because the results will guide policy and practice in oral health.

How will they benefit?
The benefits of this research will be diverse and wide-ranging. The nature of oral disease is complex and, due to its cumulative nature, inherently related to the life-course and so there will be short and long term benefits. By identifying the level of socioeconomic inequalities in oral health, where they lie and the factors and groups that could be targeted to reduce these inequalities, there is a real prospect of using the findings directly to 'fine tune' health systems to address problems arising from inequalities. There is the opportunity to feed directly into current reforms in England, but there is also relevance elsewhere in the UK and around the world. The results will inform academics and policy makers how inequalities change over time and over the life-course, and longer term, they will provide a benchmark to monitor inequalities in the future and to evaluate the impact of policies on the evolution of health inequalities.
Practitioners and patients will benefit from an understanding of vulnerable oral health groups. This has further consequences for general health and health inequalities, with conditions such as diabetes having oral symptoms identifiable at check-up. Further, by identifying vulnerable groups and determinants of inequality it can identify interventions that do not rely on the utilisation of health care services.
The academic community will benefit from the comprehensive investigation into socioeconomic inequalities in oral health. The research will provide an up-to-date set of results that academics can use as a baseline for future research into inequalities. The methods will provoke a discussion regarding the properties of the methods used, which determinants to include and their contribution to overall health inequalities. This will also fill a gap in the literature where oral health inequalities have been largely overlooked when compared to inequalities in other health outcomes.
The academic community will benefit from the comparison of the results from using objective and subjective oral health outcomes. This will be important for providing validity when subjective health outcomes are all that are available, and it will also demonstrate whether the pathways behind these health outcomes differ.