Group interventions to improve health outcomes: a framework for their design and delivery

BACKGROUND: Delivering an intervention to a group of patients to improve health outcomes is increasingly popular in public health and primary care, yet "group" is an umbrella term which encompasses a complex range of aims, theories, implementation processes and evaluation methods. We propose a framework for the design and process evaluation of health improvement interventions occurring in a group setting, which will assist practitioners, researchers and policy makers. METHODS: We reviewed the wider literature on health improvement interventions delivered to patient groups and identified a gap in the literature for designing, evaluating and reporting these interventions. We drew on our experiences conducting systematic reviews, intervention, mixed method and ethnographic studies of groups for breastfeeding and weight management. A framework for health improvement group design and delivery evolved through an iterative process of primary research, reference to the literature and research team discussion. RESULTS: Although there is an extensive literature on group processes in education, work, politics and psychological therapies, far less is known about groups where the aim is health improvement. Theories of behaviour change which are validated for individual use are often assumed to be generalisable to group settings, without being rigorously tested. Health improvement or behaviour change interventions delivered in a group setting are complex adaptive social processes with interactions between the group leader, participants, and the wider community and environment. Ecological models of health improvement, which embrace the complex relationship between behaviour, systems and the environment may be more relevant than an individual approach to behaviour change. CONCLUSION: The evidence for effectiveness and cost-effectiveness of group compared with one-to-one interventions for many areas of health improvement in public health and primary care is weak or unknown. Our proposed framework is the first step towards advocating a more systematic approach to designing, evaluating and reporting interventions in group settings, which is necessary to improve this currently weak evidence base. This framework will enable policy makers and practitioners to be better informed about what works, how it works and in which contexts when aiming to improve health in a group setting.