THE EFFECTS OF THE CHANGE! INTERVENTION ON CHILDREN'S PHYSICAL ACTIVITY AND HEALTH KELLY ALEXANDRA MACKINTOSH A thesis submitted in partial fulfilment of the requirements of Liverpool John Moores University for the degree of Doctor of Philosophy April2012 · THE FOLLOWING HAVE NOT BEEN COPIED ON INSTRUCTION FROM THE UNIVERSITY Chapter 3 Chapter 4 Appendix 3 Figure 1.1 page 22 Figure 1.2 page 24 Contact details on pages 225, 228, 232 234 and Statements The presented research programme was part of a collaborative group project entitled CHANGE! (Children's Health, Activity and Nutrition: Get Educated!). The research had the full support of Wigan Council through the PSHE-C team, as well as the Primary Care Trust. Three strands of the project included nutrition, cardiometabolic health, and physical activity. This thesis presents results from the physical activity strand of the project, within which project design, data collection, and data analyses were solely conducted. 2 Acknowledgements Firstly, I would like to thank my Director of Studies, Professor Stuart Fairclough for his continued support and guidance throughout my PhD. Stuart not only gave me the opportunity to study towards PhD, but provided me with several other great opportunities which will hopefully stand me in good stead in the future. I would also like to thank Professor Gareth Stratton for his insightful advice and support, as well as Dr Nicola Ridgers for providing me with the opportunity to enter the world of ROC analyses, not to mention her swift feedback despite being across the other side of the world! I must also thank Professor Gregory Welk for his insightful assistance concerning ROC analyses. Thank you to all the schools who allowed me access to their Year 6 children, the teachers for their time and patience, and most importantly, the children who participated in the project. A big thank you also goes to all the volunteers who assisted with data collection, and Helen Roberts and Alexandra Jones at Wigan Council who were influential in the research process. I must also thank Dr Lynne Boddy for her expert tuition inV02peak tests in children. Becky Gobbi and Genevieve Warburton ... CHANGE! wouldn't have been the same without you. Not only did we form the dream team, but I found a friend in you both. Thanks for keeping me sane and motivated in times of need. Lastly, and by no means least, I would like to thank my friends and family for always being there for me. I couldn't have done it without you. 3 Abstract Low childhood physical activity levels, and high paediatric overweight and obesity levels, carry a considerable burden to health including cardiometabolic disease, low fitness, and reduced psychosocial well-being. Numerous school- based physical activity interventions have been conducted with varied success. This thesis therefore aimed to develop and investigate the effectiveness of the Children'S Health, Activity and Nutrition: Get Educated! (CHANGE!) project, which was a school-based curriculum intervention to promote healthy lifestyles using an educational focus on physical activity and healthy eating. The purpose of the formative study (Study 1) was to elicit subjective views of children, their parents, and teachers about physical activity to inform the design of the CHANGE! intervention programme. Analyses revealed that families have a powerful and important role in promoting health-enhancing behaviours. Involvement of parents and the whole family is a strategy that could be significant to increase children's physical activity levels. There is large variation in the cut-points used to define moderate physical activity (MPA), vigorous physical activity (VPA) and sedentary time, which - impacts on accurate estimation of physical activity levels. The purpose of Study 2 was to test a field-based protocol using intermittent activities representative of children's physical activity behaviours, to generate behaviourally valid, population-specific cut-points for sedentary behaviour, MPA and VPA. These 4 cut-points were subsequently applied to CHANGE! to investigate changes in physical activity (Study 3). The CHANGE! intervention resulted in positive changes to body size and VPA outcomes after follow-up. The effects were strongest among those sociodemographic groups at greatest risk of poor health status. Further work is required to test the sustained effectiveness of this approach in the medium and long-term. Further, the development of an inexpensive and replicable field- based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve classification of physical activity levels in children, which could enhance subsequent intervention and observational studies. 5 Contents Page Page Abstract 4 List of Tables 9 List of Figures 10 Glossary of Terms 11 Chapter 1 Introduction 13 1.1:The Research Problem 14 1.2: Conceptual Framework: Green et al. (1980) Precede- 20 Proceed Model and Welk's (1999) Youth Physical Activity Promotion Model 1.3: Organisation of Thesis 26 Chapter 2 Literature Review 28 2.1: Physical Activity and Health 29 2.2: Tracking of Physical Activity, Sedentary Behaviour 35 and Obesity 2.3: Physical Activity Guidelines 35 2.4: Physical Activity Levels 39 2.5: Parental Influence on Children's Physical Activity 47 2.6: School as a Health Promotion Context 48 2.7: School-based Physical Activity Intervention Studies 50 6 2.8: Summary 55 2.9: Aims of Thesis 56 Thesis Study Map 58 Chapter 3 Study 1: Using formative research to develop 58 CHANGE!: A curriculum-based physical activity promoting intervention 3.1: Introduction 60 3.2: Methods 63 3.3: Results 68 3.4: Discussion 81 3.5: Conclusions 87 Thesis Study Map 89 Chapter 4 Study 2: A calibration protocol for population- 89 specific accelerometer cut-points in children 4.1: Introduction 91 4.2: Methods 93 4.3: Results 101 4.4: Discussion 104 4.5: Conclusions 110 Thesis Study Map 110 7 Chapter 5 Study 3: Promoting healthy body size in primary school 114 children through physical activity education: The CHANGE! intervention 5.1: Introduction 115 5.2: Methods 118 5.3: Results 137 5.4: Discussion 147 5.5: Conclusions 159 Thesis Study Map 160 Chapter 6 Synthesis 162 Chapter 7 Conclusions 170 Chapter 8 Recommendations 173 8.1: Recommendations for practice 174 8.2: Recommendations for future research 175 References 177 Appendices 220 Appendix 1: Ethical approval 221 Appendix 2: ActiGraph instructions 235 Appendix 3: Associated publications 239 8 List of Tables Page Table 3.1. Example interview questions 66 Table 4.1. Participant characteristics 94 Table 4.2. Descriptions of the activities performed by children 95 Table 4.3. ROC-derived cut-points for accelerometer counts per 102 minute (CPM) Table 4.4. Comparison of classification agreement, sensitivity, 103 specificity, and kappa coefficients for different cut-points using cross-validation data (free-play and DVD watching) Table 5.1. CHANGE! themes, lesson titles and content summary 123 Table 5.2. Descriptive characteristics of Control and Intervention 138 children at baseline, post-intervention, and follow-up Table 5.3. Unadjusted physical activity outcome measures of Control 138 .and Intervention children at baseline, post-intervention, and follow-up Table 5.4. Unadjusted body size outcome measures of Control 138 and Intervention children at baseline, post-intervention, and follow-up Table 5.5. Multilevel model analyses of overall physical activity and 144 sedentary time Table 5.6. Multilevel model analyses of body size outcomes 145 9