Title: BEhavioural Weight Management: COMponents of Effectiveness (BE:COME)
Funder: Department of Health and Social Care

Abstract: Behavioural weight management interventions (BWMIs) are the main funded treatment for obesity in the UK. Most often these are community-based groups which meet weekly for 12 weeks, focusing on diet, physical activity and behavioural change. There are national guidelines on what a BWMI should contain, but they are vague and only cover a small part of what makes up a BWMI. It has been difficult to compare BWMIs and see what works best because researchers have used different ways to describe the weight-loss results in studies, or do not fully describe what the BWMIs involved for participants. _x000D_ _x000D_ BWMIs are complicated and they can be made up of very different parts. For example, one BWMI may have exercise classes every week but another may simply give advice on being more active. These differences are seen across the recommended diets, the help for people to plan and stick to the BWMI (like keeping a diary of what you eat or setting targets for how much weight to lose), and things related to how the BWMI is run, such as the training of the staff or how far people need to travel to take part. No one is sure what works best. It may be that the same BWMI will not work as well for everyone; younger adults, men, ethnic minorities or those from deprived backgrounds may have different needs. As there is doubt as to what types of BWMIs work best, in many areas of the UK no BWMIs are funded at all._x000D_ _x000D_ What is this research about?_x000D_ We want to find out which parts of BWMIs are linked to weight-loss, and what the best combination of parts is for different groups of people taking part. _x000D_ _x000D_ How will the study be carried out?_x000D_ We have already got agreement from 30 BWMIs in the UK to share data on who attended and their change in weight. We also have permission to re-use data from 8 research trials of UK BWMIs that finished in the last 10 years. We will work closely with each BWMI so we can describe them in detail. A group of expert advisors (including members of the public) will decide on around 10 parts of BWMIs for us to study that they think may be related to better completion rates and higher weight loss, and yet are not part of every BWMI just now. The research trials and real-life BWMIs will then be compared using a special technique called component network meta-analysis. This technique allows the different parts that make up the BWMIs to be compared. By doing this for a range of groups of people we will be able to say which parts of the BWMIs are linked to weight loss for each group. For any part that is linked to weight loss, we will work out if the likely health benefits outweigh the costs of delivering it._x000D_ _x000D_ How will we involve the public? How will we share the results?_x000D_ 3 members of the public with personal experience of weight management will be part of the advisory group and one further person will be on the main research team. As well as selecting the BWMI parts to be studied, we will ask them for guidance on putting the results into practice and sharing them with the public. We will also ask key existing patient involvement groups, such as young people from deprived backgrounds and ethnic minority communities, for their opinions. At the end of the study we will invite the BWMIs that took part, the advisory group (including public members), and policy-makers from across the UK, to attend a one-day meeting. We will present the results and work together to create a practical guide for adding these parts into BWMIs across the UK.

Lay abstract: Which individual components of adult behavioural weight management programmes are associated with greater effectiveness?_x000D_ Behavioural weight management interventions (BWMIs) are the main funded interventions for obesity in the UK but there is high intervention variability including by mode of delivery, dietary, physical activity and behavioural components. Systematic reviews funded by NICE and Public Health England (PHE) list major limitations in the current published evidence including the lack of detailed intervention descriptions & standardised outcome measures, and lack of published studies that reflect services in the UK. Due to the poor evidence base, current NICE guidance (PH53) covers only a fraction of the variable components of a weight management intervention and NICE have developed a specific research recommendation “… what effect do specific components of a multicomponent lifestyle weight management programme have on adherence, effectiveness and cost effectiveness."_x000D_ Aims: To determine which individual components of behavioural weight management programmes are associated with greater attendance, intervention completion, and weight loss; if the individual components of BWMIs are more effective when delivered on their own/ in combination; if the effects of individual/groups of components vary depending on the sex, age, BMI, ethnicity or socioeconomic status of participants; the cost-effectiveness of any individual/ groups of components found to be effective._x000D_ Methods: _x000D_ We have written agreement for collaboration from 30 real world interventions and 8 UK-based_x000D_ RCTs (n= 77,943 participants). All interventions will be described using our standardised reporting template. An independent advisory group (inc PPI) will decide on ~10 components which vary across the interventions and are hypothesised to be of importance. A core outcome set developed by consensus will be applied assessing weight loss, attendance, & completion over 12 weeks of active intervention._x000D_ 1. We will conduct network meta-analysis (NMA) at intervention and at component level using data from the RCTs. In the component NMA, the effect of each intervention will be dismantled through_x000D_ modelling of component-specific effects. _x000D_ 2. We will determine the comparative effectiveness of individual real-world services using an unanchored, population-adjusted indirect comparison approach to estimate relative effectiveness of interventions._x000D_ 3. We will bring together the RCT and observational data in an NMA and explore the potential of using CNMA, through the use of three-level hierarchical models._x000D_ 4. We will use a multivariate meta-regression approach to assess consistency across the body of evidence. _x000D_ 5. The PHE Weight Management Economic Assessment Tool will be used to assess cost effectiveness of the addition of components identified as effective._x000D_ Timelines: -6-6m approvals; 1-9m transfer data; 5-7m intervention descriptions; 9m STOP-GO criteria (data for 10 RWS & 5 RCTs); 10m protocol agreed; 11-30m data management & analysis; 31m dissemination meeting; 32m final report_x000D_ Impact and dissemination: The impact of this work will be better guidance on the effective components of BWMIs leading to the commissioning of more effective interventions. All contributing sites and representatives from the 4 nations’ public health bodies, will be invited to meet (month 31) to discuss the implementation of results and develop a toolkit to be shared with commissioners and providers.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL
Health categories: CANCER AND NEOPLASMS;CARDIOVASCULAR;METABOLIC AND ENDOCRINE;ORAL AND GASTROINTESTINAL;STROKE