Development of a peer support intervention to encourage dietary behaviour change towards a Mediterranean diet in adults at high cardiovascular risk

McEvoy et al. BMC Public Health (2018) 18:1194 https://doi.org/10.1186/s12889-018-6108-z RESEARCH ARTICLE Open Access Development of a peer support intervention to encourage dietary behaviour change towards a Mediterranean diet in adults at high cardiovascular risk Claire T. McEvoy1* , Sarah E. Moore1, Katherine M. Appleton2, Margaret E. Cupples1,3, Christina Erwin1, Frank Kee1,3, Lindsay Prior3, Ian S. Young1,3, Michelle C. McKinley1,3 and Jayne V. Woodside1,3 Abstract Background: Mediterranean diet (MD) interventions are demonstrated to significantly reduce cardiovascular disease (CVD) risk but are typically resource intensive and delivered by health professionals. There is considerable interest to develop interventions that target sustained dietary behaviour change and that are feasible to scale-up for wider public health benefit. The aim of this paper is to describe the process used to develop a peer support intervention to encourage dietary behaviour change towards a MD in non-Mediterranean adults at high CVD risk. Methods: The Medical Research Council (MRC) and Behaviour Change Wheel (BCW) frameworks and the COM-B (Capability, Opportunity, Motivation, Behaviour) theoretical model were used to guide the intervention development process. We used a combination of evidence synthesis and qualitative research with the target population, health professionals, and community health personnel to develop the intervention over three main stages: (1) we identified the evidence base and selected dietary behaviours that needed to change, (2) we developed a theoretical basis for how the intervention might encourage behaviour change towards a MD and selected intervention functions that could drive the desired MD behaviour change, and (3) we defined the intervention content and modelled outcomes. Results: A theory-based, culturally tailored, peer support intervention was developed to specifically target behaviour change towards a MD in the target population. The intervention was a group-based program delivered by trained peer volunteers over 12-months, and incorporated strategies to enhance social support, self-efficacy, problem-solving, knowledge, and attitudes to address identified barriers to adopting a MD from the COM-B analysis. Conclusions: The MRC and BCW frameworks provided a systematic and complementary process for development of a theory-based peer support intervention to encourage dietary behaviour change towards a MD in non-Mediterranean adults at high CVD risk. The next step is to evaluate feasibility, acceptability, and diet behaviour change outcomes in response to the peer support intervention (change towards a MD and nutrient biomarkers) using a randomized controlled trial design. Keywords: Mediterranean diet, peer support, behaviour change wheel, interventiondevelopment * Correspondence: 1 Centre for Public Health, Queen’s University Belfast, Grosvenor Road, Belfast BT12 6BJ, UK Full list of author information is available at the end of the article © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. McEvoy et al. BMC Public Health (2018) 18:1194 Background Cardiovascular disease (CVD) and type 2 diabetes (T2DM) are major public health concerns. Risk of these diseases can be significantly reduced by modifying lifestyle behaviours, such as diet. The Mediterranean diet (MD), rich in fruit, vegetables, wholegrain, nuts, olive oil and oily fish, low in processed foods and moderate in alcohol intake, is rated as the most likely dietary pattern to protect against coronary disease [1] and has been demonstrated, in a randomised controlled trial (RCT) setting, to significantly reduce the risk of developing CVD [2] and T2DM [3]. However, previous interventions to encourage MD behaviour change have used resource intensive methods [2, 3] which may be challenging for some healthcare systems to roll out to an ‘at risk’ or general population. There is a need to understand how to support dietary behaviour change toward a MD, particularly in non-Mediterranean population (adults living in a non-Mediterranean country), using approaches that are cost-effective, practical and feasible to implement for public health. Peer support, defined as: ‘the provision of emotional, appraisal, and informational assistance by a created social network member who possesses experiential knowledge of a specific behaviour or stressor and similar characteristics as the target population, to address a health-related issue’ [4], may offer an alternative method of encouraging dietary change. One RCT, to date, has focused on a peer support behaviour change intervention promoting the MD. A six-month trial of the Mediterranean Lifestyle Programme demonstrated significant improvements in dietary behaviour and glycaemic control in postmenopausal women with existing diabetes [5]. This intervention targeted several health behaviours, including diet, physical activity, smoking and stress, and was delivered using a combination of peer and health professional support strategies. To our knowledge, there are no RCTs examining the effectiveness of exclusive peer-led support on adoption of a MD. Dietary behaviour is complex and influenced by many factors interacting at psychological, social and environmental levels [6, 7]. Complex interventions aimed at changing behaviour often contain a number of components that can act independently and inter-dependently [8]. To date, there is limited evidence of the effectiveness of dietary interventions for sustained behaviour change [9] which may, in part, be attributable to inadequate intervention design [10]. There is a need to better understand how dietary interventions work, for whom, and in what context, to enable reproducibility of interventions and allow for effective translation of research into public health policy. Designing a dietary behaviour intervention is a process that requires planning [11]. The most recent Medical Research Council (MRC) framework [11] provides guidance for the systematic development and testing of complex health interventions. A phased iterative approach Page 2 of 13 consisting of development, feasibility and piloting, evaluation and implementation, is recommended, and has been applied in the development of complex health interventions across a wide variety of populations and settings [12–16]. The MRC framework advises that intervention design should be based on a theoretical understanding (...truncated)