Effect of a peer support intervention to encourage adoption and maintenance of a Mediterranean diet in established community groups: A cluster randomised trial

Abstract

Background and objectives: Peer support offers a potential alternative, low cost social support approach to encouraging lifestyle behaviour change. The Trial to Encourage Adoption and Mainte nance of a MEditerranean Diet (TEAM-MED) was designed to pilot test a peer support (PS) programme and compare this to a proven intensive Mediterranean Diet (MD) intervention and a minimal MD education intervention for encouraging adoption of the MD in adults at high CVD risk in Northern Ireland (NI). TEAM-MED PS groups were newly formed, however, research suggests that leveraging existing social networks in established groups can enhance the effectiveness of peer support strategies and further encourage behaviour change. This study is an extension of TEAM-MED aiming to explore the effect of the PS intervention when compared to a minimal education intervention in already established community groups. Methods: NI based community groups were recruited through established community links and randomised to receive a PS intervention or a minimal education intervention. Trained peer supporters delivered the PS intervention over a 12-month period; this consisted of 11 group-based sessions each lasting 2 hours. The minimal intervention group received written educational literature focusing on the MD. Mediterranean Diet Score (MDS) was assessed at baseline, 3, 6 and 12 months. The primary outcome was change in habitual MDS at 6 months from baseline (adoption). Change in MDS at 12 months from 6 months (maintenance) is a secondary outcome. Results: Four community groups recruited: n=2 randomised to the PS intervention and n=2 to the minimal education intervention, with n=8 participants per group. At 6 months, MDS increased by 2.6±2.7 in the PS intervention and 3.3±2.2 in the education group, from baseline; the between group difference was non-significant after adjusting for baseline scores (-0.9 (95%CI-2.9, 1.2)) (p=0.39). Conclusions: It is possible that the true effect of the peer support intervention may be underestimated due to the comparison with a minimal education intervention. One year follow-up results (June 2017) will allow the evaluation of whether the PS intervention encourages the maintenance of a MD longer term. Findings will inform a future large-scale RCT where the efficacy and cost-effectiveness of the peer support MD intervention will be tested.