Author: Rebecca Anne Perry
Perry, Rebecca Anne, 2008 Family management of overweight in 5-9 year old children: results from a multi-site randomised controlled trial, Flinders University, School of Medicine
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Childhood overweight is a leading global public health issue. Chapter One of this thesis is a three part literature review of the evidence concerning the issue of childhood overweight and its management. Section One of the literature review describes this issue in terms of Australian and international prevalence rates and trends, health outcomes and aetiology. Sections Two and Three of the literature review examine the evidence to guide effective management of childhood overweight and analyse the thoroughness by which this evidence has been determined and translated into practice recommendations. The assumed cornerstones of child weight management are dietary change, increased physical activity, decreased sedentary behaviour, family support and behaviour modification. Recently, the role of parenting skills in the management of childhood overweight has been identified as a promising area of research. This thesis study examined the effect of the addition of parenting skills training to a parent-led, family-focussed healthy lifestyle intervention for the management of overweight in 5-9 year old children (The Parenting, Eating and Activity for Child Health (PEACH) Study). The methodology of the intervention is presented in Chapter Two. Families of overweight 5-9 year old children across two sites (three cohorts per site) were randomized to either a healthy lifestyle group program (HL) or a healthy lifestyle plus parenting group program (HL+P). Parents in both groups received eight 1.5hour group education sessions covering topics on child/family nutrition, physical activity and positive body image. Parents in the HL+P group were offered a four week parenting skills training program prior to this. All information was directed to parents and they were responsible for initiating and maintaining healthy lifestyle changes with their families. The intervention was delivered over a six month period and group differences were examined at this time point (intervention effect) and six months following with no further program contact (maintenance effect). The sample size (n=169) was calculated to demonstrate an estimated reduction in BMI z-score of 30% in the HL+P group and 10% in the HL group over 12 months, allowing for a drop out rate of one third (power=80%, significance=95%). Intention to treat analysis was conducted using ANCOVA. The effectiveness of the intervention was measured against a comprehensive evaluation plan consisting of: • primary outcome indicators (body mass index (BMI) z-score and waist circumference (WC) z-score) (Chapter Three), • secondary outcome indicators (health-related quality of life (HRQoL), body size dissatisfaction and height z-score) (Chapter Three), • impact evaluation indicators (children’s lifestyle behaviours and parent’s parenting practices) (Chapter Four), • process evaluation indicators (participant attendance and satisfaction and maintenance of program integrity across sites) (Chapter Four) and • qualitative evaluation of the factors external to the intervention that supported or inhibited families to achieve their healthy lifestyle goals (Chapter Five). Analysis of the primary outcomes (Chapter Three) found a significant group difference at the six month time point for BMI z-score (HL: -8%, HL+P: -13%, p=0.005), but not WC z-score (HL: -9%, HL+P: -11%, p=0.39). There were no group differences at the 12 month time point (six months following intervention end and with no further program contact). Application of the IOTF definition for childhood overweight and obesity to the full study sample found that 39 (23%) and 130 (77%) children were classified as overweight and obese respectively at baseline. By the six month time point (n=135), six (4%) children fell within the healthy weight range and 38% were classified as overweight and 58% as obese. At 12 months (n=123), 4% of children remained in the healthy weight range, 35% as overweight and 61% as obese. Children’s psychosocial health and linear growth were sustained during the intervention and maintenance periods. There were no between-group difference observed for any of the children’s lifestyle behaviours (dietary and activity behaviours) or parents’ parenting practices. However, the group as a whole exhibited significant improvements from baseline for scores of diet quality at the six month time point that were maintained during the following six month non-contact period (p<0.001 for 0-6mth and 0-12mth) (Chapter Four). Small screen usage significantly decreased for the full sample from 0-6 months and 0-12months (p<0.001 for both), however time spent being physically active did not change. Parents in both groups reported improvements in aspects of parenting over both time periods. Evaluation of process indicators showed that the intervention was well attended and accepted by families (Chapter Four). Seventy three percent (123) of subjects were retained to the 12 month time point and 44% (75) attended at least 75% of scheduled program sessions. Of the 131 parents who responded to a program satisfaction questionnaire, ninety four percent reported receiving the help they desired and 99% would recommend the program to others. The integrity of intervention sessions was upheld across sites providing reassurance that the program protocol was adhered to and demonstrating a good degree of generalisability. The thematic analysis of interviews conducted with parents at the 12month time point identified more references to barriers than facilitators of healthy lifestyle goal achievement (433 vs 375) (Chapter Five). This chapter highlights the contextual nature of family-based interventions and weight management strategies and the need to consider these during program planning and delivery. Chapter Six concludes the thesis by summarising its results and highlighting how they have contributed to the evidence base. Study strengths and limitations are described and implications of the findings on practice and future research are presented.
Keywords: child weight management,family,parent
Subject: Medicine thesis, Nutrition thesis
Thesis type: Doctor of Philosophy
School: School of Medicine
Supervisor: Dr Anthea Magarey, Prof Lynne Daniels, Prof Michael Sawyer