Systematic development of a complex intervention: a theory and evidence-based physiotherapist led group intervention to increase physical activity and reduce sedentary behaviour following bariatric surgery (PARIS)

Objectives To describe the systematic development of a physiotherapist led group behaviour change intervention targeting physical activity and sedentary behaviour in individuals who have undergone bariatric surgery. Study design Intervention development including evidence synthesis, qualitative research and mapping of intervention components, using the 2008 MRC framework for complex interventions. Methods We conducted a systematic review to identify the evidence for promising interventions and components to increase physical activity and reduce sedentary behaviour following bariatric surgery. We also conducted primary qualitative research exploring these behaviours with three key stakeholder groups: patients, clinicians and commissioners. We selected two contemporary behaviour change frameworks to inform intervention development and developed a conceptual matrix in which intervention objectives were defined to inform selection of appropriate behaviour change techniques, proposed mechanisms of action(s), and mode of delivery. We also developed two intervention handbooks for participants and facilitators to support delivery and receipt of the intervention. Results We have developed a behaviour change intervention targeting physical activity and sedentary behaviour in patients following bariatric surgery. Eight intervention objectives were defined and mapped to the Behaviour Change Wheel and Theoretical Domains Framework. We identified what the intervention must be able to do (intervention functions), behaviour change techniques that could be used to achieve this, the proposed mechanism of action, and mode of delivery. This intervention will be subject to a feasibility study, with the intervention delivered online over a six-week period to participants who have had bariatric surgery within the previous five years.