Parent and child perceptions of school-based obesity prevention in England: a qualitative study.

BACKGROUND: Schools are key settings for childhood obesity prevention, and the location for many intervention studies. This qualitative study aims to explore parent and child experiences of the WAVES study obesity prevention intervention, in order to gain understanding of the mechanisms by which the intervention results in behaviour change, and provide context to support interpretation of the main trial results. METHODS: Focus groups were held with 30 parents and 62 children (aged 6-7 years) from primary schools in the West Midlands, UK. Data analysis (conducted using NVivo 10) was guided by the Framework Approach. RESULTS: Three over-arching themes were identified: 'Impact', 'Sustainability' and 'Responsibilities', under which sub-themes were determined. Participants were supportive of the school-based intervention. Parental involvement and the influential role of the teacher were seen as key ingredients for success in promoting consistent messages and empowering some parents to make positive behavioural changes at home. Parents recognised that whilst they held the primary responsibility for obesity prevention in their children, they faced a number of barriers to healthier lifestyles, and agreed that schools have an important role to play. CONCLUSIONS: This study enabled us to better understand aspects of the WAVES study intervention programme that have the potential to initiate positive behaviour changes in families, and indicated that a combination of pathways influenced such changes. Pathways included: increasing capability through improving knowledge and skills of children and parents; increasing motivation through parental empowerment and role modelling; and the direct provision of opportunities to lead healthier lifestyles. Strategies to sustain behaviour changes, and the school role in supporting these, are important considerations.

A cluster-randomised controlled trial to assess the effectiveness and cost-effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6-7 year old children: the WAVES study protocol.

BACKGROUND: There is some evidence that school-based interventions are effective in preventing childhood obesity. However, longer term outcomes, equity of effects and cost-effectiveness of interventions have not been assessed. The aim of this trial is to assess the clinical and cost-effectiveness of a multi-component intervention programme targeting the school and family environment through primary schools, in preventing obesity in 6-7 year old children, compared to usual practice. METHODS: This cluster randomised controlled trial is set in 54 primary schools within the West Midlands, UK, including a multi-ethnic, socioeconomically diverse population of children aged 6-7 years. The 12-month intervention consists of healthy diet and physical activity promotion. These include: activities to increase time spent doing physical activity within the school day, participation in the 'Villa Vitality' programme (a programme that is delivered by an iconic sporting institution (Aston Villa Football Club), which provides interactive learning opportunities for physical activity and healthy eating), healthy cooking skills workshops in school time for parents and children, and provision of information to families signposting local leisure opportunities. The primary (clinical) outcome is the difference in body mass index (BMI) z-scores between arms at 3 and 18 months post-intervention completion. Cost per Quality Adjusted Life Year (QALY) will also be assessed. The sample size estimate (1000 children split across 50 schools at follow-up) is based on 90% power to detect differences in BMI z-score of 0.25 (estimated ICC ≤ 0.04), assuming a correlation between baseline and follow-up BMI z-score of 0.9. Treatment effects will be examined using mixed model ANCOVA. Primary analysis will adjust for baseline BMI z-score, and secondary analysis will adjust for pre-specified baseline school and child level covariates. DISCUSSION: The West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study is the first trial that will examine the cost-effectiveness and long term outcomes of a childhood obesity prevention programme in a multi-ethnic population, with a sufficient sample size to detect clinically important differences in adiposity. The intervention was developed using the Medical Research Council framework for complex interventions, and outcomes are measured objectively, together with a comprehensive process evaluation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN97000586 (registered May 2010).

Process evaluation design in a cluster randomised controlled childhood obesity prevention trial: the WAVES study.

BACKGROUND: The implementation of a complex intervention is heavily influenced by individual context. Variation in implementation and tailoring of the intervention to the particular context will occur, even in a trial setting. It is recognised that in trials, evaluating the process of implementation of a complex intervention is important, yet process evaluation methods are rarely reported. The WAVES study is a cluster randomised controlled trial to evaluate the effectiveness of an obesity prevention intervention programme targeting children aged 6-7 years, delivered by teachers in primary schools across the West Midlands, UK. The intervention promoted activities encouraging physical activity and healthy eating. This paper presents the methods used to assess implementation of the intervention. METHODS: Previous literature was used to identify the dimensions of intervention process and implementation to be assessed, including adherence, exposure, quality of delivery, participant responsiveness, context, and programme differentiation. RESULTS: Multiple methods and tools were developed to capture information on all these dimensions. These included observations, logbooks, qualitative evaluation, questionnaires and research team reflection. DISCUSSION: Data collection posed several challenges, predominantly when relying on teachers to complete paperwork, which they saw as burdensome on top of their teaching responsibilities. However, the use of multiple methods helped to ensure data on each dimension, where possible, was collected using more than one method. This also allowed for triangulation of the findings when several data sources on any one dimension were available. CONCLUSIONS: We have reported a comprehensive approach to the assessment of the implementation and processes of a complex childhood obesity prevention intervention within a cluster randomised controlled trial. These approaches can be transferred and adapted for use in other complex intervention trials. TRIAL REGISTRATION NUMBER: ISRCTN97000586.

Tracking changes in weight status in primary school children in Birmingham: an analysis of the National Child Measurement Programme - a retrospective cohort study.

One-in-four 4-5 years and more than one-in-three 10-11 years have excess weight in England. AIM: To identify characteristics associated with (1) having overweight, obesity and severe obesity at 11 years and (2) rapid weight gain (defined as increasing weight status by one or more body mass index (BMI) categories) between the ages of 4-5 and 10-11 years. METHOD: Using National Child Measurement Programme data, BMI at reception (4-5 years) and year 6 (10-11 years) were linked for 15 390 children. Weight categories were identified at both time points using BMI centile classifications.For each child, the number of BMI categories they crossed between reception and year 6 was identified. Logistic regression models were fitted to explore associations with sociodemographic characteristics of children with excess weight at age 10-11 years and with children experiencing rapid weight gain between reception and year 6. RESULTS: Overall, 61.9% of children remained in their original weight category; 30% whose weight increased by ≥1 weight categories and 11.7% by ≥2 weight categories. Only 7.8% had decreased ≥1 weight categories and 0.9% had decreased ≥2 weight categories.Adjusting for other sociodemographic characteristics, girls were less likely than boys to increase ≥2 weight categories between reception and year 6 (OR 0.64; 95% CI 0.58 to 0.71; p<0.001). Compared to white children, Asian and mixed-ethnicity children had higher odds of rapid weight gain. Children with the highest deprivation were over 6 times more likely to increase ≥2 weight categories between reception and year 6 compared with children with the lowest deprivation (OR 6.1; 95% CI 1.92 to 19.10; p<0.01). CONCLUSION: Male children, children of Asian and mixed ethnicity and children with high deprivation are at higher risk of rapid weight gain and should be targeted for intervention.

Body image, body dissatisfaction and weight status in South Asian children: a cross-sectional study.

BACKGROUND: Childhood obesity is a continuing problem in the UK and South Asian children represent a group that are particularly vulnerable to its health consequences. The relationship between body dissatisfaction and obesity is well documented in older children and adults, but is less clear in young children, particularly South Asians. A better understanding of this relationship in young South Asian children will inform the design and delivery of obesity intervention programmes. The aim of this study is to describe body image size perception and dissatisfaction, and their relationship to weight status in primary school aged UK South Asian children. METHODS: Objective measures of height and weight were undertaken on 574 predominantly South Asian children aged 5-7 (296 boys and 278 girls). BMI z-scores, and weight status (underweight, healthy weight, overweight or obese) were calculated based on the UK 1990 BMI reference charts. Figure rating scales were used to assess perceived body image size (asking children to identify their perceived body size) and dissatisfaction (difference between perceived current and ideal body size). The relationship between these and weight status were examined using multivariate analyses. RESULTS: Perceived body image size was positively associated with weight status (partial regression coefficient for overweight/obese vs. non-overweight/obese was 0.63 (95% CI 0.26-0.99) and for BMI z-score was 0.21 (95% CI 0.10-0.31), adjusted for sex, age and ethnicity). Body dissatisfaction was also associated with weight status, with overweight and obese children more likely to select thinner ideal body size than healthy weight children (adjusted partial regression coefficient for overweight/obese vs. non-overweight/obese was 1.47 (95% CI 0.99-1.96) and for BMI z-score was 0.54 (95% CI 0.40-0.67)). CONCLUSIONS: Awareness of body image size and increasing body dissatisfaction with higher weight status is established at a young age in this population. This needs to be considered when designing interventions to reduce obesity in young children, in terms of both benefits and harms.

An exploration of the longitudinal relation between parental feeding practices and child anthropometric adiposity measures from the West Midlands Active Lifestyle and Healthy Eating in Schoolchildren (WAVES) Study.

Background: Some research suggests that parent or carer feeding practices may influence children's weight patterns, but longitudinal evidence is limited and inconsistent. Objective: The aim of this study was to investigate the relation between various parent or carer feeding practices when a child is aged 7-8 y and proxy measurements of child adiposity at age 8-9 y (weight status, waist-to-height ratio, and body fat percentage). Design: The study was a secondary analysis of data from the West Midlands Active Lifestyle and Healthy Eating in Schoolchildren (WAVES) Study comprising a diverse sample of parents and carers and their children from 54 primary schools in the West Midlands, England [n = 774 parent-child dyads (53% of the WAVES study sample)]. Information on feeding practices was collected with the use of subscales from the Comprehensive Feeding Practices Questionnaire, completed by the child's main parent or carer (self-defined). Child height, weight, bioelectrical impedance, and waist circumference were measured and converted into 3 proxy measurements of adiposity (weight status, waist-to-height ratio, and body fat percentage). Associations between these measurements and parent or carer feeding practices were examined with the use of mixed-effects logistic regression models. Results: Of the questionnaire respondents, 80% were mothers, 16% were fathers, and 4% were other carers. Median standardized subscale scores ranged from 1.7 (emotion regulation: IQR = 1.0) to 4.0 (monitoring and modeling: IQR = 1.5), and significantly different subscale scores were present between child weight statuses for emotion regulation, pressure to eat, and restriction for weight control. Logistic regression modeling showed that when baseline adiposity measures were included as covariates, all associations between parental feeding practices at age 7-8 y and measures of adiposity at age 8-9 y were attenuated. Conclusions: Observed relations between various parental feeding practices and later adiposity are mitigated by inclusion of the baseline adiposity measure. This finding lends support to the theory of reverse causation, whereby the child's size may influence parental choice of specific feeding practices rather than the child's subsequent weight status being a consequence of these feeding practices.

Effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6 and 7 year olds: cluster randomised controlled trial (WAVES study).

OBJECTIVE: To assess the effectiveness of a school and family based healthy lifestyle programme (WAVES intervention) compared with usual practice, in preventing childhood obesity. DESIGN: Cluster randomised controlled trial. SETTING: UK primary schools from the West Midlands. PARTICIPANTS: 200 schools were randomly selected from all state run primary schools within 35 miles of the study centre (n=980), oversampling those with high minority ethnic populations. These schools were randomly ordered and sequentially invited to participate. 144 eligible schools were approached to achieve the target recruitment of 54 schools. After baseline measurements 1467 year 1 pupils aged 5 and 6 years (control: 28 schools, 778 pupils) were randomised, using a blocked balancing algorithm. 53 schools remained in the trial and data on 1287 (87.7%) and 1169 (79.7%) pupils were available at first follow-up (15 month) and second follow-up (30 month), respectively. INTERVENTIONS: The 12 month intervention encouraged healthy eating and physical activity, including a daily additional 30 minute school time physical activity opportunity, a six week interactive skill based programme in conjunction with Aston Villa football club, signposting of local family physical activity opportunities through mail-outs every six months, and termly school led family workshops on healthy cooking skills. MAIN OUTCOME MEASURES: The protocol defined primary outcomes, assessed blind to allocation, were between arm difference in body mass index (BMI) z score at 15 and 30 months. Secondary outcomes were further anthropometric, dietary, physical activity, and psychological measurements, and difference in BMI z score at 39 months in a subset. RESULTS: Data for primary outcome analyses were: baseline, 54 schools: 1392 pupils (732 controls); first follow-up (15 months post-baseline), 53 schools: 1249 pupils (675 controls); second follow-up (30 months post-baseline), 53 schools: 1145 pupils (621 controls). The mean BMI z score was non-significantly lower in the intervention arm compared with the control arm at 15 months (mean difference -0.075 (95% confidence interval -0.183 to 0.033, P=0.18) in the baseline adjusted models. At 30 months the mean difference was -0.027 (-0.137 to 0.083, P=0.63). There was no statistically significant difference between groups for other anthropometric, dietary, physical activity, or psychological measurements (including assessment of harm). CONCLUSIONS: The primary analyses suggest that this experiential focused intervention had no statistically significant effect on BMI z score or on preventing childhood obesity. Schools are unlikely to impact on the childhood obesity epidemic by incorporating such interventions without wider support across multiple sectors and environments. TRIAL REGISTRATION: Current Controlled Trials ISRCTN97000586.

The West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study: a cluster randomised controlled trial testing the clinical effectiveness and cost-effectiveness of a multifaceted obesity prevention intervention programme targeted at children aged 6-7 years.

BACKGROUND: Systematic reviews suggest that school-based interventions can be effective in preventing childhood obesity, but better-designed trials are needed that consider costs, process, equity, potential harms and longer-term outcomes. OBJECTIVE: To assess the clinical effectiveness and cost-effectiveness of the WAVES (West Midlands ActiVe lifestyle and healthy Eating in School children) study intervention, compared with usual practice, in preventing obesity among primary school children. DESIGN: A cluster randomised controlled trial, split across two groups, which were randomised using a blocked balancing algorithm. Schools/participants could not be blinded to trial arm. Measurement staff were blind to allocation arm as far as possible. SETTING: Primary schools, West Midlands, UK. PARTICIPANTS: Schools within a 35-mile radius of the study centre and all year 1 pupils (aged 5-6 years) were eligible. Schools with a higher proportion of pupils from minority ethnic populations were oversampled to enable subgroup analyses. INTERVENTIONS: The 12-month intervention encouraged healthy eating/physical activity (PA) by (1) helping teachers to provide 30 minutes of additional daily PA, (2) promoting 'Villa Vitality' (interactive healthy lifestyles learning, in an inspirational setting), (3) running school-based healthy cooking skills/education workshops for parents and children and (4) highlighting information to families with regard to local PA opportunities. MAIN OUTCOME MEASURES: The primary outcomes were the difference in body mass index z-scores (BMI-zs) between arms (adjusted for baseline body mass index) at 3 and 18 months post intervention (clinical outcome), and cost per quality-adjusted life-year (QALY) (cost-effectiveness outcome). The secondary outcomes were further anthropometric, dietary, PA and psychological measurements, and the difference in BMI-z between arms at 27 months post intervention in a subset of schools. RESULTS: Two groups of schools were randomised: 27 in 2011 (n = 650 pupils) [group 1 (G1)] and another 27 in 2012 (n = 817 pupils) [group 2 (G2)]. Primary outcome data were available at first follow-up (n = 1249 pupils) and second follow-up (n = 1145 pupils) from 53 schools. The mean difference (MD) in BMI-z between the control and intervention arms was -0.075 [95% confidence interval (CI) -0.183 to 0.033] and -0.027 (95% CI -0.137 to 0.083) at 3 and 18 months post intervention, respectively. The main analyses showed no evidence of between-arm differences for any secondary outcomes. Third follow-up included data on 467 pupils from 27 G1 schools, and showed a statistically significant difference in BMI-z (MD -0.20, 95% CI -0.40 to -0.01). The mean cost of the intervention was £266.35 per consented child (£155.53 per child receiving the intervention). The incremental cost-effectiveness ratio associated with the base case was £46,083 per QALY (best case £26,804 per QALY), suggesting that the intervention was not cost-effective. LIMITATIONS: The presence of baseline primary outcome imbalance between the arms, and interschool variation in fidelity of intervention delivery. CONCLUSIONS: The primary analyses show no evidence of clinical effectiveness or cost-effectiveness of the WAVES study intervention. A post hoc analysis, driven by findings at third follow-up, suggests a possible intervention effect, which could have been attenuated by baseline imbalances. There was no evidence of an intervention effect on measures of diet or PA and no evidence of harm. FUTURE WORK: A realist evidence synthesis could provide insights into contextual factors and strategies for future interventions. School-based interventions need to be integrated within a wider societal framework and supported by upstream interventions. TRIAL REGISTRATION: Current Controlled Trials ISRCTN97000586. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 8. See the NIHR Journals Library website for further project information.

Are school physical activity characteristics associated with weight status in primary school children? A multilevel cross-sectional analysis of routine surveillance data.

BACKGROUND: The school environment potentially influences the development of childhood obesity. Changes to schooling could be used as an intervention to reduce obesity but the features of the school environment that influence obesity are unknown. AIM: To estimate the interschool variation in body mass index (BMI) z-scores in primary school children and examine the individual and school physical activity characteristics contributing to this. METHODS: Cross-sectional analysis and multilevel modelling at individual and school level, with BMI SD scores (z-scores) as the outcome. Individual and school data were obtained for 11 118 reception year children (age 4-5) and 10 151 year 6 children (age 10-11) from 296 primary schools in Birmingham. Data sources were the UK National Child Measurement Programme and the annual National School Sport Survey in 2006/7. RESULTS: In reception year children, 4.2% of the variation in BMI z-scores is attributed to differences between schools. Individual characteristics explained 24% of this between-school variation and certain school physical activity characteristics (the time schools devote to physical education) explained a further 28%. In year 6 children, only 0.9% of the variation in BMI z-scores was between-school variation. BMI z-scores were significantly higher in year 6 than reception year children, with the largest increases between year groups in the South Asian and African-Caribbean ethnic groups. Deprivation was positively associated with BMI z-scores. CONCLUSIONS: In addition to the association between individual characteristics and BMI z-score, there is a small but significant association between school characteristics and BMI z-score, which is in part explained by the time schools devote to physical education. This modest school effect has the potential to have a substantial impact on children's weight status at a population level.

Preventing childhood obesity, phase II feasibility study focusing on South Asians: BEACHeS.

OBJECTIVE: To assess feasibility and acceptability of a multifaceted, culturally appropriate intervention for preventing obesity in South Asian children, and to obtain data to inform sample size for a definitive trial. DESIGN: Phase II feasibility study of a complex intervention. SETTING: 8 primary schools in inner city Birmingham, UK, within populations that are predominantly South Asian. PARTICIPANTS: 1090 children aged 6-8 years took part in the intervention. 571 (85.9% from South Asian background) underwent baseline measures. 85.5% (n=488) were followed up 2 years later. INTERVENTIONS: The 1-year intervention consisted of school-based and family-based activities, targeting dietary and physical activity behaviours. The intervention was modified and refined throughout the period of delivery. MAIN OUTCOME MEASURES: Acceptability and feasibility of the intervention and of measurements required to assess outcomes in a definitive trial. The difference in body mass index (BMI) z-score between arms was used to inform sample size calculations for a definitive trial. RESULTS: Some intervention components (increasing school physical activity opportunities, family cooking skills workshops, signposting of local leisure facilities and attending day event at a football club) were feasible and acceptable. Other components were acceptable, but not feasible. Promoting walking groups was neither acceptable nor feasible. At follow-up, children in the intervention compared with the control group were less likely to be obese (OR 0.41; 0.19 to 0.89), and had lower adjusted BMI z-score (-0.15 kg/m(2); 95% CI -0.27 to -0.03). CONCLUSIONS: The feasibility study informed components for an intervention programme. The favourable direction of outcome for weight status in the intervention group supports the need for a definitive trial. A cluster randomised controlled trial is now underway to assess the clinical and cost-effectiveness of the intervention. TRIAL REGISTRATION NUMBER: ISRCTN51016370.