How are treatment outcomes for people with severe obesity ImPROved by GROUP-based behavioural intervention?

Background Severe obesity (Body Mass Index >35kg/m2) affects approximately 5 million people in the UK, shortens life expectancy and is a risk factor for many health problems. Annually, obesity costs the NHS £2.5-5.1 billion.

The NHS commissions specialist ( Tier 3 ) clinics for lifestyle management of severe obesity but the challenge is how to deliver these effectively and efficiently, particularly with rising demand. Group-based interventions may help respond to this challenge.

Research question This 5-year programme addresses questions concerning: (i) feasibility of a group-based intervention for people with severe obesity (PWSO); (ii) (cost-) effectiveness of, and (iii) mechanisms underpinning, group-based interventions for PWSO; (iv) service implementation of such interventions.

Aims and objectives To test an evidence-based group intervention ( PROGROUP ) for reducing weight in PWSO.

Specific objectives are to: Refine the PROGROUP intervention, and the logic model and implementation strategy which underpin it Assess feasibility and acceptability of PROGROUP and proposed trial methods Test whether PROGROUP is more effective than usual care, in terms of supporting weight loss and other health outcomes Evaluate PROGROUP cost-effectiveness and mechanisms of action Determine how best to implement PROGROUP.

Overall design Three linked work-packages (WPs) will refine the intervention and its logic model; assess the delivery feasibility and methodology for, and then conduct, a definitive randomised controlled trial; finalise and disseminate the implementation strategy. Patient and public involvement (PPI) The research programme is underpinned by extensive PPI work.

Patients and other stakeholders (health care professionals, service managers) will be involved throughout, including in the project dissemination.

WP1: Preparing for delivery of group-based intervention in Tier 3 settings Advisory group consultations Realist evaluation of logic model Assemble intervention manual and training programme Finalise the outcome measure set Finalise sites and permissions Map baseline resource use in trial sites WP2: Assessing feasibility Two-arm randomised feasibility study of PROGROUP in three sites to explore common feasibility concerns and intervention processes, and confirm health (economic) outcome measures Decide whether or not to progress to definitive trial WP3: Assessing effectiveness and cost-effectiveness Final procedures and parameters will be based on WPs1-2.

Current proposal: Pragmatic, superiority, individually randomised controlled trial (N=1,100), delivered in 10 sites Parallel process and health economic evaluation Finalisation of implementation strategy Dissemination Dissemination will be structured using NIHR s Push the Pace guidance and dissemination template, and will include: An end-of-project stakeholder event to share new guidance on implementing group-based intervention in Tier 3 services Dissemination to national and international health care professionals through stakeholder organisations (including the Association for the Study of Obesity) Peer-reviewed publications and conference presentations Anticipated impact Anticipated short, medium, and long-term benefits for patients and the NHS include: Short: Enhancing patient engagement with group-based care; production of guidelines for optimising Tier 3 services Medium: Weight loss necessary to bring about health benefits in a greater proportion of patients; trained facilitators demonstrating competence in running groups Long: Weight loss maintenance and sustained behaviour change; consistency in provision and improved cost effectiveness of NHS Tier 3 care.