This trial is registered as ISRCTN55309164.
Funding
Chapter 1 Introduction
T
his feasibility study was commissioned by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme. The remit was to develop an intervention to reduce alcohol consumption in obese men and to assess the feasibility of a trial investigating the effectiveness of an intervention. The intervention used the motivation of weight loss to promote moderated drinking. The commissioning brief is included at the end of the report (see Appendix 1). This chapter provides the scientific background and the aims and objectives of the study, and gives an overview of the study methods. It also outlines the structure of the report, as well as detailing ethics approval and modifications to the protocol.Background
Heavy alcohol consumption by men who are obese increases their risk of death from liver disease 19-fold.1 Having a raised body mass index (BMI) and consuming> 14 units of alcohol per week are both factors that independently increase the risk of liver disease. However, the combination of the two leads to a substantially greater risk.1The commissioning brief described this as the supra-additive effect of obesity and alcohol. The problem is compounded by the high prevalence of heavy drinking and of obesity. The English Health Survey 20122found that 24% of men aged≥16 years drank more than the then government-recommended 21 units per week. Data from 2011 revealed that 24% of men in England3 and 28% of men in Scotland4were obese. Based on current trends, the UK government’s Foresight programme predicted an increase in the prevalence of obesity among men.5Furthermore, heavy alcohol consumption is associated with an increased risk of obesity.6–8Abdominal obesity is more common among men who drink beer.9Heavy drinking leads to overeating,10thus increasing the potential for weight gain. An intervention that could reduce both alcohol consumption and weight in obese men could make a significant contribution to improving public health. However, it is far from certain that obese men who drink heavily would engage in such an intervention. They may not regard their drinking as problematic and may not think it could contribute to weight gain. Many obese men want to lose weight, but are reluctant to try conventional weight loss approaches, because these are generally targeted at women.11Men are under-represented in weight loss interventions12and attrition is high in weight loss studies.13,14
Previous research has identified many features of an intervention that could make it attractive to potential male participants. Convenience and compatibility with a busy life are important,15–17as is the use of community settings for intervention delivery.18The style and tone should be relaxed and friendly as
opposed to strict and regimented.16,17The content should be personalised and accessible,15,18but should be delivered in a matter-of-fact way.18,19The aim of the intervention should also be realistic and achievable.17 The recently completed Football Fans in Training study20,21provides an excellent example of an engaging community-based intervention that effectively changed behaviour. This previous research clarifies many of the requirements of an intervention for obese men. The present study aims to identify the specific content that would be required to change their drinking behaviour and to assess the feasibility of a trial to test the effectiveness of the intervention.
The feasibility study
This study aimed to develop a gender-specific extended alcohol intervention that could reduce alcohol consumption among obese men. The remit stated that it should use the motivation of weight loss to achieve this. The study also aimed to develop and test all the methods for a randomised controlled trial (RCT) of this intervention. Feasibility/pilot studies provide the opportunity to test and improve all study procedures.22,23Guidance from national funding bodies in the UK24and Canada25stress the need for these preliminary studies. The intention is to ensure that design weaknesses, technical problems and methodological flaws do not compromise the full RCT.26
The challenges for this feasibility study arise from the nature of the study group and the design and delivery of the intervention. Identifying obese men who drink heavily could be difficult. Recruiting and retaining these men in the study would require a study design that elicits and sustains engagement. Part of the intervention was to be delivered by laypeople (study co-ordinators) whose training and support are crucial to the effective delivery of the intervention. Finally, sensitive process measures would be required to determine the fidelity of delivery and the extent to which there is engagement with the intervention. The objectives for the feasibility study were:
1. to determine the best ways to recruit and retain obese men in a study aimed at reducing heavy drinking 2. to design an intervention that is an acceptable way to achieve a sustained reduction in alcohol consumption 3. to identify the content and timing of the delivery that is most likely to engage obese men in an
intervention to reduce alcohol consumption
4. to develop high-quality training to enable the trained laypeople (study co-ordinators) to deliver their component of the intervention
5. to devise process measures to detect engagement with the steps on the causal model for behaviour change 6. to compile a manual of methods for participant recruitment, the training of lay staff and the design and
delivery of the intervention. The use of language
This study dealt with the issue of obesity but avoided the use of this term except in a few places. There were several reasons for avoiding the term obesity. People can be sensitive to terminology and do not like to be classified as‘obese’.16,27–29Possibly the term is associated with pictures of extreme overweight seen in media images27and would therefore appear inappropriate. This is supported by the finding that most men who are obese consider themselves to be overweight rather than obese, and some consider themselves to be of normal weight.30Obesity is considered a medical term that conveys society’s disapproval of overweight people.28Thus, the term very overweight was preferred to obese.