A randomised controlled trial to test the effectiveness of a brief intervention for weight management for obese adults in primary care.

Obesity, a major cause of chronic disease, affects 25% of adults. Even a small loss of weight is likely to reduce the risk of chronic diseases occurring, such as diabetes that are the consequence of being overweight. We can use lessons learnt from tobacco control and apply these to obesity. GPs make unsolicited brief interventions frequently on smoking and problem drinking, which are known to be effective in changing patients' behaviour. A key aim of the smoking cessation brief interventions is to refer patients to the NHS Stop Smoking Service, which treated 750,000 people last year in England. Available data suggest GPs rarely bring up weight issues opportunistically and do not know what they could say that would be helpful. Available data also suggest patients who are overweight would like more advice on this from their doctors.

Recent evidence has shown that attending a commercial weight management service, such as Weight Watchers, is more effective than any other widely available alternative weight loss intervention in primary care. In England, referral to commercial weight management is available free to patients on the NHS voucher scheme or equivalent.

We therefore propose a trial in which GPs will bring up the issue of weight with patients presenting to their GP for reasons other than weight management. Patients will be randomised to one of two interventions. In the control group, the GP will encourage weight loss because this will benefit health. In the intervention group, GPs will advocate referral to a weight management service and make that referral immediately. They will also offer a review about a month later to check progress. The main outcome will be weight loss at one year, but we will also record participants' and GPs' reactions to both types of interventions.

The trial results could make the case for brief interventions for obese people consulting their GP and introduce widespread simple treatments akin to the effective NHS Stop Smoking Service. The intervention makes only very modest demands on a GP's time and skills. If successful and implemented widely, it will increase a GP's engagement with weight loss and maintenance. Likewise, the intervention could be introduced into the GP pay for performance scheme and could influence practice worldwide.

Obesity affects 25% of the UK's adult population but modest weight loss can reduce the incidence of obesity-related chronic disease. Some effective weight loss treatments exist but there is no nationally available NHS treatment service and GPs rarely discuss weight management with patients or support behaviour change. Evidence shows that commercial weight management services, that most PCTs have 'on prescription', are more effective than primary care treatment. We propose a controlled trial where patients will be randomised to receive either the offer of help by referral to a weight management service and follow-up to assess progress or advice to lose weight on medical grounds. The primary outcome will be weight change at 12-months. Other questions are: What actions do people take to manage their weight in response to the two GP intervention types? How do obese patients feel about GPs opportunistically discussing weight management and how does this vary by intervention type? How do GPs feel about raising the issue opportunistically and giving the two types of brief intervention? What is the cost per kg/m2 lost for each intervention? Research assistants visiting GP practices in the West Midlands (n=60) would objectively measure weight and height prior to GP consultations and randomise willing patients (BMI 30+, 18+ years) using sealed envelopes. Full recruitment (n=1824) is feasible in 46 weeks, requiring 6 sessions of advice-giving per GP. Participants will be contacted at 3-months (post intervention) via telephone, to identify actions they have taken to manage their weight. We will book appointments for participants to be seen at their GP practice for a 12-month follow-up. Trial results could make the case for brief interventions for obese people consulting their GP and introduce widespread simple treatments akin to the NHS Stop Smoking Service. Likewise, the intervention could be introduced in the Quality and Outcomes Framework and influence practice worldwide.

The key non-academic beneficiaries are obese people with weight problems consulting their doctor, doctors, future commissioners of public health interventions, such as Public Health England and GP consortia, the National Institute of Health and Clinical Excellence (NICE) (who oversee recommendations on health policy), the Department of Health, and providers of weight loss services.

People with weight problems report that they want their doctor to discuss this issue and help them manage their weight, but the available evidence suggests that doctors do this infrequently. Furthermore, interventions are generally focused on advice to lose weight, not on effective interventions. Should this intervention prove effective, this could lead to relatively rapid changes in clinical practice that will change the experience for patients. Currently most interventions doctors make focus on the consequences of obesity, such as treating hypertension or diabetes, where some treatments make weight loss harder. The results of this trial could introduce preventative medical action before people develop the complications of obesity, which people say that they want.

Doctors report a lack of knowledge and a corresponding lack of confidence in managing obesity. Although our research does not directly tackle this, depending on the results, it could provide doctors with an evidence-based management strategy that would increase their confidence to discuss weight issues with their patients.

Policy makers, represented by NICE and the various UK health departments are direct beneficiaries and hold the key to implementing the results of this research. NICE has published guidelines on the identification and management of obesity and is also responsible for the Quality and Outcomes Framework (QOF) for GPs. The QOF currently rewards GPs for identifying obesity but not for any active management, unlike all other clinical areas, reflecting the gap in evidence that our trial would fill. Through our contacts with the NICE QOF process and because NICE guidelines are updated regularly, we believe that implementation of the results of this research will follow shortly after publication, if the results are positive.

Providers of weight loss services may benefit from the study findings if positive, because they would encourage doctors to refer to these services. It will be a decision for the NHS whether they wish to engage with any willing provider, the current policy, or develop its own NHS weight management services. These providers generate jobs and tax revenue within the UK.

The researchers will benefit. Amanda Lewis is a newly appointed post-doctoral worker and will work as co-PI alongside Paul Aveyard and other senior members of the investigator team, who are experienced in running trials in primary care. In so-doing, she will develop skills and experience that will allow her to develop as an independent researcher. We will also appoint a trial manager and it is our aspiration that s/he would register for a part-time PhD to use the data from the trial. In doing so, s/he would train in a UKCRC centre of excellence in public health research with a growing team of researchers in behavioural medicine. The link with the MRC Centre for Human Nutrition Research that this application embodies will also link with another UKCRC centre of excellence and a broader range of research on weight management.

More broadly, there are gains from prevention, such as reducing sickness absence, reduced health care costs, and improved health and quality of life.