The trial aims to assess the clinical and cost-effectiveness of a programme of activities to encourage healthy lifestyle choices among children aged 6-7 years with the aim of helping them maintain a healthy weight. The trial is set in the West Midlands, UK, within a multiethnic population.
The multifaceted 12 month intervention programme targets the school and family environments and consists of elements to encourage both healthy eating and physical activity in children. The elements included in the intervention programme were informed by a developmental study that was guided by the early phases of the UK Medical Research Council framework for complex interventions (Birmingham healthy Eating & Active lifestyle for Children Study (BEACHeS)).
Summary of the study...
To help primary school aged children maintain a healthy weight and thereby prevent overweight and obesity through increasing physical activity and promoting healthy eating by working with schools and communities.
Type of study and funding information
The WAVES study is a cluster randomised controlled trial of an obesity prevention programme. It is a high profile study based in schools and communities in the West Midlands and the results will inform and feed into national policy and government plans. The programme of activities included in the intervention was developed and piloted (in some Birmingham schools) by a research team in the School of Health and Population Sciences at the University of Birmingham. This pilot work showed promising initial findings and the research team competed with researchers nationally to become successful in securing a prestigious grant from the National Institute for Health Research Health Technology Assessment (NIHR – HTA) programme to undertake the WAVES study.
Details of intervention programme
There are 4 key elements to the intervention programme:
1) Initiatives to increase the amount of daily physical activity children undertake in school by 30 minutes. Schools have 3 main options to choose from in order to achieve this:
- Delivering a structured programme of activity during lunch time.
- A programme involving short bursts of physical activity either at the start and end
of the school day or between lessons.
- The Take-10 programme which provides lesson plans that include a physical
activity element to deliver components of the curriculum.
In schools allocated to receive the intervention, individual discussions are undertaken to ascertain what activities the school already undertakes, and based on that, which of the physical activity option(s) would work best in their setting. Relevant school staff are supported as required to help them start to deliver the selected activities.
2) Healthy cooking workshops delivered to children and their parents in school. Three such sessions are delivered (one in each term during the intervention year). These sessions are delivered by school staff as part of a school day and parents are invited to attend. School staff delivering these sessions attend a training day run by the research team to ensure an appropriate level of nutrition knowledge and to familiarise them with the format of the sessions.
3) Participation of children in the ‘Villa Vitality’ (VV) programme, a course of 3 sessions run over 6 weeks by Aston Villa football club, involving physical activity opportunities and interactive learning sessions on healthy eating. The VV programme was originally developed for an older age group (Year 6) but has been adapted for use in the current study with children in Year 2 (aged 6-7 years).
4) Provision of information to families that gives ideas on how to be active over the summer and that signposts local physical activity and leisure opportunities. The information on summer activity ideas is provided to Year 1 pupils and their families in intervention schools before schools break up for the summer holidays. The signposting information is provided as early as possible in the Autumn term when the children have just started in Year 2.
How the intervention programme will be evaluated
A sampling frame including 980 local education authority maintained primary schools in the West Midlands within a 35 miles radius of Birmingham was produced. From this sampling frame 200 schools were selected for invitation using a weighted random sample to try to ensure a wide socioeconomic, ethnic and geographic mix. From this list schools were invited in batches until 54 schools had been recruited to participate in the study. Checks for response bias were undertaken in between each set of invitations sent out but no statistically significant bias was observed.
For participating schools there are 3 main stages to the study:
During the Spring term, Year 1 children and parents in all participating schools are asked to take part in the study through their school. Children for whom we have consent are then assessed in several ways during the Summer term when they are still in Year 1. The assessments include physical measurements such as height, weight, skin-fold thickness and blood pressure, and a short interview to assess their sense of well-being. Food intake and objective physical activity levels are also measured. In addition, parents are asked to complete questionnaires.
The childhood obesity prevention programme is then introduced to half of the schools and communities participating in the study for one school year, when the children are in Year 2. These schools are randomly selected from all schools who agree to participate after measurements in all schools have been completed. Measurements will be taken for all children, including schools who do not receive the programme, so that results can be compared between schools receiving and not receiving the programme.
The participating children and parents will be assessed in the same way as stage 1, after the intervention programme has finished, when the children are in Year 3. The assessments will also be repeated yearly for one or two years, to assess the longer term effectiveness of the programme.
The study will run over 5 years.
Timing of the study
Although the study involves 54 schools direct involvement with the study has been in two phases. Half (ie 27) of the schools (phase 1) became involved in the 2010/2011 school year with Year 1 pupil and parent recruitment taking place from January to April 2011 (Spring term 2010/2011) and measurements being undertaken from May to July 2011 (Summer term 2010/2011). For schools in phase 1 that were randomly allocated to receive the obesity prevention programme it was delivered in the 2011/2012 school year when the measured pupils were in Year 2. Follow up measures for children from both the intervention and control schools will be undertaken from September to December 2012, January to April 2014 and September to December 2014.
The other half of the schools (phase 2) began direct involvement in the 2011/2012 school year. Year 1 pupil and parent recruitment took place from January to April 2012 (Spring term 2011/2012) with measurements from May to July 2012 (Summer term 2011/2012). For schools in phase 2 that are randomly allocated to receive the obesity prevention programme it will be delivered in the 2012/2013 school year when the measured pupils will be in Year 2. Follow up measures for children from both the intervention and control phase 2 schools will be undertaken from September to December 2013 and January to April 2015.
Measures to be used to assess the effectiveness of the intervention
The primary outcome measure is the change in BMI z-scores (standardised deviation scores) and this will be compared in control and intervention schools at follow up, taking account of clustering, baseline levels and other relevant co-variates. An important secondary outcome is difference between baseline and follow up in the percentage of children categorised as normal weight, overweight and obese in control compared to intervention schools, using BMI cut-offs based on the UK 1990 reference charts.
Other outcome measures that will be considered include differences between control and intervention clusters in:
Diet – dietary energy intake, dietary fat, sugar and fruit and vegetable intake;
Physical activity – total physical activity expenditure, time spent in sedentary, light, moderate and vigorous physical activity;
Quality of life and other psychological outcomes.
In addition, an economic evaluation will also be undertaken, for which the main outcome measure will be an estimate of cost per ‘case of overweight/obesity prevented’.