Obesity Prevention Innovation Pathway (OPIP)

Background

Being overweight or obese may severely impact quality and length of life, it also increases the risk of developing other conditions such as type 2 diabetes and cardiovascular disease. The continued rise of obesity also places an increased pressure on health and care services. Tirzepatide (Mounjaro) has been approved for use in the NHS as a treatment for obesity and for people who are clinically overweight, however eligibility depends on BMI and how many weight-related health conditions someone has.

NICE Technology Appraisal TA1026 recommends Mounjaro for obesity management alongside dietary and physical activity interventions. However, NHS guidance states that 3.4 million patients are potentially eligible for Mounjaro under the NICE criteria. The size of the population groups presents challenges for the delivery of Mounjaro in the NHS within the expected NICE timeframe of 3 months, because of the practical and financial implications for already stretched local NHS systems.

Funded by UKRI Innovate UK and Eli Lilly, The Obesity Pathway Innovation Programme (OPIP) has been setup to fund 12 local NHS systems across the UK to create innovative ways of delivering weight management services including a mixture of GP led delivery, digital, physical, hybrid, community-based services and access to pharmacotherapy.

• Read the press release (gov.uk) for further information.

The National Institute for Health and Care Research (NIHR) have approached REVAL to evaluate the early implementation of OPIP.

What we are doing

There are three phases to the OPIP evaluation.

Phase 1: Sense-making and mapping of new service models of care

Timeframe: March to August 2026

Phase 1 focuses on understanding and describing the new OPIP service models before and during their early rollout. The aim is to build a clear picture of how services have been designed, who they are intended to support, and how they will operate in practice.

Phase 2: Early implementation 

Timeframe: September 2026 to October 2027  

Phase 2 examines how the new services are being implemented in practice and what resources are required to deliver them. This phase of the evaluation focuses on early service delivery, implementation experiences, service utilisation and anticipated costs.

Across phases 1 and 2 the evaluation will aim to: 

• Map and describe the new service delivery models of care, including rationale, underpinning assumptions and equity considerations in the design and early implementation;
• Map and describe the characteristics of the target patient populations: those eligible to receive services and those in receipt of services;
• Assess the availability of routine data on service delivery, utilisation and anticipated outcomes;
• Co-produce a ‘core evaluation dataset’ that will address evidence end-user knowledge requirements;
• Understand contextual factors influencing early implementation of the new service models including key enablers/facilitators of service design and setup;
• Explore the cost and resource impact of the new service models;
• Establish a framework for longitudinal evaluation in Phase 3 (to be commissioned by NIHR).

Phase 3: Evaluation

Timeframe: To be confirmed

This will be a longitudinal evaluation of impact and will be delivered by a different evaluation team.