Oral health promotion in preschool children. Prospective study of the determinants of oral health-related behaviour. In-depth evaluation of the 'Smile for Life' intervention programme.

Dental caries remains one of the most common infectious diseases in preschool children. In Flanders, one out of three five-year-olds presented with visible caries experience. As oral health is to a great extent determined by behavioural factors, intervention studies have been developed aimed at reducing dental decay or at improving oral health-related behaviours by educational programmes for parents. The Smile for Life programme was developed based on the available evidence and consisted of a multi-component intervention that was built on a theoretical framework, i.e. the Theory of Planned Behaviour (TPB). Use has been made of a pre-post test design with a control group to measure effect Despite these efforts, only limited effects of the programme could be observed at the level of oral health and reported behaviour.The aim of this PhD was to explain the limited effects of the Smile for Life study. Six hypotheses, grouped in three categories, were formulated. It was investigated (A) whether the programme design was insufficient, (B) whether the intervention was only effective on the level of the psychological determinants or in subgroups and (C) whether the intervention was poorly implemented. (A). The TPB components turned out to be significant predictors of intentions and behaviours related to oral health, arguing for the reliability and validity of the developed questionnaire. However, future research should indicate whether other theoretical backgrounds can serve as a better basis to develop oral health interventions or whether other behavioural change techniques, such as skills training or motivational interviewing, are more effective. (B.) There were no effects of the intervention on the level of the TPB-determinants (attitudes, subjective norms, perceived behavioural control, intention), nor any effects in subgroups of participants. Besides, natural changes in the TPB-determinants were observed as the child grew older. High-educated mothers had better attitudes, perceived behavioural control, intentions and oral health-related behaviours towards their children, who also presented with better oral health. This indicates the need for targeted interventions for low- and high-educated parents. (C). The process analysis indicated that the intervention was generally implemented as prescribed in the manual, although lower attendance rates at the consultations as well as the restricted time to spend on the oral health topics were the largest threats to implementation fidelity.A combination of factors can explain the limited effects. First, the interpretation of the effects was impeded through the general improvement of oral health in Flanders and a possible response bias in the control group. In addition, implementation constraints, the limited application of effective behavioural change techniques and the exclusion of the children from low socio-economic backgrounds can explain part of the limited effect. Because complex interventions are not often evaluated in depth, this research adds new and original knowledge to the field and serves as a basis for developing more targeted and effective preventive interventions.Chapter 1. General introduction 1 1 Preface 3 2 Theory-informed health promotion 3 3 The ‘Smile for Life’ oral health intervention 6 3.1 Dental caries in preschool children: prevalence and symptoms 6 3.2 Risk factors 7 3.3 Theoretical background Fout! Bladwijzer niet gedefinieerd. 3.4 Participants, design and measurements 10 4 Evaluation of oral health promotion interventions 5 Chapter 2. Objectives 19 Chapter 3. Measuring determinants of oral health behaviour in parents of preschool children. 25 1 Introduction 29 2 Methods 30 3 Results 33 4 Discussion 35 Chapter 4. Predicting oral health-related behaviour in preschool children: An application of the Theory of Planned Behaviour in parents and health care workers. 45 1 Introduction 49 2 Methods 50 3 Results 52 4 Discussion 55 Chapter 5. Effect of time and socio-economic status on the determinants of oral health-related behaviours of parents of preschool children. 67 1 Introduction 72 2 Methods 74 3 Results 78 4 Discussion 82 Chapter 6. Oral health and oral health-related behaviour in preschool children: evidence for a social gradient 91 1 Introduction 97 2 Methods 98 3 Results 100 4 Discussion 102 Chapter 7. Evaluating the implementation fidelity of a multi-component intervention for oral health promotion in preschool children 115 1 Introduction 119 2 Methods 121 3 Results 126 4 Discussion 129 Chapter 8. Impact of intervention dose in oral health promotion in preschool children 141 1 Introduction 145 2 Methods 146 3 Results 149 4 Discussion 151 Chapter 9. Effect evaluation of an oral health promotion intervention in preschool children 161 1 Introduction 165 2 Methods 166 3 Results 168 4 Discussion 170 Chapter 10. General discussion 181 1 Overview of the main findings 185 1.1 Was the programme design insufficient? 185 1.2 Was the intervention only effective at the level of the psychological determinants or in subgroups? 186 1.3 Was the intervention poorly implemented? 187 2 Towards an explanation of the limited effects 189 3 Strengths and limitations 191 3.1 The ‘Smile for life’ study 191 3.2 The evaluation study 193 4 Recommendations 195 4.1 For research 195 4.2 For policy 197 4.3 For the preventive health services (Child and Family) 198 5 Conclusion 200nrpages: 229status: publishe