Northern Ireland (NI) has the poorest levels of oral health in the United Kingdom (UK) with its children having the highest levels of tooth decay in Europe (Department of Health, Social Services and Public Safety; DHSSPS, 2007). The Oral Health Strategy for Northern Ireland (DHSSPS, 2007) emphasises the need to address these problems, yet there is a lack of research investigating the determinants of young people's toothbrushing behaviour. This study sought to address this research gap by investigating young peoples attitudes and motivations for brushing their teeth. To achieve this aim a mixed-methods sequential research design was employed, with the Theory of Planned Behaviour (TPB) providing the theoretical framework for each of the research stages. In stage one, an elicitation study adopting focus group methodology was conducted to elicit the modal salient beliefs of the target behaviour. These beliefs were then used to inform the development of items contained within the TPB questionnaire. In stage two, the research sought to confirm suitability of the questionnaire measure for use with the target group, schoolchildren aged 9-10 years. Test-retest methodology was employed to explore the psychometric properties of each scale. In stage three, the study investigated the theoretical factors influencing toothbrushing intentions and behaviour among 867 schoolchildren. Participation in the research study was recruited using randomised and stratified sampling techniques. Overall, the findings provide support for the theoretical model of the TPB and highlight the key theoretical constructs in predicting intentions to brush teeth among schoolchildren, namely self-efficacy, attitude and subjective norm. They have also elucidated the relative importance of the factors that are influential in affecting childrens motivations and decisions to brush their teeth. Furthermore, the study has highlighted the important contribution of other variables affecting childrens toothbrushing behaviour such as, various risk factors can impinge upon their toothbrushing routine, including tiredness, laziness, memory and issues related to resources (e.g. types of toothpaste and texture of toothbrush). This study undoubtedly provides support for the theoretical model of the TPB. The questionnaire measure was found to be a valid and reliable instrument for assessing toothbrushing beliefs of schoolchildren, suggesting that the theory is applicable for use with a child population. The findings from this study could be of use to those interested in designing interventions to reduce Nl's oral health problem and given the theoretical framework, identify those factors which influence toothbrushing behaviour amongst a particularly at-risk group. It is hoped that the research will make a valid contribution to the TPB-based literature and also serve as a possible framework for other health psychologists interested in this topic.

Dissertation (Ph.D.)--University of South Florida, 2008. / Title from PDF of title page. Document formatted into pages; contains 239 pages. Includes vita. Includes bibliographical references.