Raising awareness of what constitutes a healthy weight range and the need to stay within such a range

What is the effectiveness of public health interventions and the media to increase awareness of importance of staying a healthy weight?

What is the effectiveness of public health interventions and the media to increase awareness of behaviours associated with maintenance of a healthy weight (diet and activity)?

How can interventions best engage population/target groups?

Is an increase in awareness translated into action?

Identifying adults and children who should participate in prevention programmes based on their risk factors for obesity and readiness and opportunities to change their behaviour

What is the effectiveness of public health interventions to identify individuals who would benefit from participation in prevention/public health interventions to manage weight?

What are the existing UK and non-UK guidelines/recommendation in relation to identifying individuals who would benefit from participation in prevention/public health interventions to manage weight?

Maintaining energy balance in adults and children of a healthy weight through a healthy diet and physical activity

What are the factors helping individuals to maintain energy balance/prevent overweight and obesity?

What are the factors helping individuals to increase their activity levels to an extent which will help maintain energy balance/prevent overweight and obesity?

What are the factors helping individuals to improve their diet in such a way to help maintain energy balance/prevent overweight and obesity?

Community-based services including those to which individuals are referred from primary care services

What is the effectiveness of interventions through community based public health services in terms of helping individuals/populations maintain a healthy weight/prevent overweight or obesity?

What is the effectiveness of interventions through community-based public health services in terms of helping individuals/populations improve behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies are effective in engaging a broad range of organisations and encouraging partnerships?

Broader environmental interventions in the community

What is the effectiveness of broader environmental interventions in terms of helping individuals/populations maintain a healthy weight/prevent overweight or obesity?

What is the effectiveness of broader environmental interventions in terms of helping individuals/populations improve behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies are effective in engaging a broad range of organisations and encouraging partnerships?

Interventions in workplaces

What is the effectiveness of workplace interventions in terms of helping individuals/populations to maintain a healthy weight/prevent overweight or obesity?

What is the effectiveness of workplace interventions in terms of helping individuals/populations improving behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies are effective in attracting workplaces to invest in the health and activity of their workforce?

Interventions in schools

What is the effectiveness of school interventions in terms of helping individuals/populations maintain a healthy weight/prevent overweight or obesity?

What is the effectiveness of school interventions in terms of helping individuals/populations to improve behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies are effective in engaging schools to undertake interventions?

What are the essential elements of a ‘whole schools approach’?

Interventions targeted at children aged 2–5 years

What is the effectiveness of interventions targeted at 2–5-year-olds, and their families/carers, in terms of helping children maintain a healthy weight/preventing overweight or obesity?

What is the effectiveness of interventions targeted at 2–5-year-olds, and their families/carers, in terms of helping children to improve behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies (identified in 8.1 or 8.2) are most effective in terms of participation and retention and which factors contribute to this success?

Interventions targeted at black and minority ethnic groups, at vulnerable groups and at individuals at vulnerable life-stages

What is the effectiveness of interventions to help vulnerable groups maintain a healthy weight/prevent overweight or obesity?

What is the effectiveness of interventions to help vulnerable groups improve behaviours associated with maintenance of a healthy weight (diet and activity)?

What strategies (identified in 9.1 or 9.2) are most effective in terms of participation and retention and which factors contribute to this success?

Interventions to manage overweight and obesity in non-clinical settings

What is the effectiveness of interventions in non-clinical settings (i.e. community-based and including commercial and self management) to help manage overweight or obesity?

What is the effectiveness of interventions in non-clinical settings (i.e. community-based and including commercial and self management) to help overweight and obese groups improve behaviours (diet and activity) associated with weight loss?

What non-clinical (i.e. community-based) strategies are associated with the maintenance of weight loss and continuation of improved behaviours (diet and activity) among overweight and obese individuals?

Study year and type

• Rapid review to include search for interventions and evaluations and also cohort, qualitative and survey studies for corroborative evidence.
• In line with NICE methodology, if sufficient high quality, up-to-date evidence is found for a specific question, older studies and/or those using weaker designs will not be examined.
• English language papers only will be included.
• Papers not held at the British Library will be excluded.

Evidence of effectiveness

• Weight outcomes – include all RCTs and all controlled clinical (non-randomised) trials (CCTs) from 1990. To ensure that any key data published pre 1990 is not overlooked, an additional search of the Cochrane Trial database 1966–89 to be undertaken and any relevant RCTs included. In addition, where systematic reviews (published 1995 onwards) are identified, any included RCTs published before 1990 to be considered in rapid review. For topic areas with limited or no RCT/CCT evidence we will use the best available evidence.
• Intermediate outcomes (i.e. physical activity and diet) – include systematic review evidence from 1995 plus more recent RCTs and CCTs where available. For topic areas with limited or no systematic reviews, RCT/CCTs we will use the best available evidence.
• Cost outcomes – as intermediate outcomes (NB: this criteria for rapid reviews; additional search on costs likely to be undertaken).
• Changes in knowledge, attitudes and awareness alone will not be considered within the main body of reviews but will be considered in a separate ‘mini review’. This restriction is due to time constraints.

Cohort studies

(NB: of particular relevance to review addressing The Determinants of Weight gain and Weight Maintenance)

• Prospective cohorts of at least 12 months duration that assessed factors potentially associated with weight gain or weight control in adults and/or children who were not all obese at baseline and reported a weight outcome at baseline and follow-up included.
• There are no structured reporting requirements for observational longitudinal studies. Tooth et al. (2005) have recently developed and tested a checklist.

Corroborative evidence

• Evidence from UK to be included in all reviews. Relevance of evidence from outside UK to considered by question though ability to include constrained by time limitations.

Length of follow-up

• Minimum requirement for studies of effectiveness is at least one data point before and one after the intervention.
• Minimum time period of 3 months between baseline and repeat measures for interventions.

Treatment of systematic reviews

• To avoid ‘double counting’, where more than one systematic review is available to answer a question, the ‘best systematic review’ will be included. The ‘best’ will invariably be the most recent but older reviews will be included if better quality than more recent reviews. The excluded review(s) will be checked to ensure all appropriate studies included.

‘Unpicking’ individual studies within systematic reviews

• The need to ‘unpick’ the ‘best’ available systematic review to its individual study components should be considered on a ‘case-by-case’ basis.
• Where a review is judged to be of high quality and meets the NICE inclusion criteria, there is no need to unpick the review down to the components of individual studies. However, where the reviewers are in some doubt as to the quality of the review, or there are concerns about the lack of intervention detail presented within the review, then the review should be unpicked.
• The outcome measures and follow up time are critical in determining the need to unpick a review (i.e. a review that includes two different studies, one with a 2-week follow-up time and the other with 4-month follow-up should be unpicked).
• The benefits of ‘unpicking’ a review should be carefully balanced against time constraints.

Combining systematic reviews and individual studies

• Where a systematic review and a more recent individual study are identified, the approach should be to update the review rather than treating the review and study separately. However, how reviews and individual studies are combined should be the judgement of reviewers.
• NICE technical team to advise where there is some doubt as to how specific review(s) and studies should be combined.

Grading systematic reviews

• The grade of review should be based on the study type for which the conclusions are primarily based (i.e. if a review included five RCTs and fifteen CCTs but overall conclusions predominantly based on CCT evidence, then grade should be as a review of CCTs not as a review of RCTs).

Critical appraisal tools

• There is not currently a NICE appraisal tool for non-randomised controlled studies. Agreed that reviewers should use relevant EPOC forms as where NICE tools are not currently available.

Intention to treat

• To use the Cochrane Handbook definition of intention to treat (ITT) (see section 8.4; http://www.cochrane.dk/cochrane/handbook/hbook.htm).
• Contrary to current NICE guidelines, where RCTs do not include ITT the quality of the study should be downgraded, not the study type.
• It was agreed that the lack of ITT is a quality issue and not a design issue and that the current NICE methodology handbook is incorrect in implying that RCTs without ITT should be ‘downgraded’ to non-RCTs.