T2D is a chronic, metabolic disease characterised by elevated levels of blood glucose in the absence of treatment. It is caused by defects in insulin secretion, insulin action or both. Over time, high blood glucose levels can cause damage to many major organs including the heart, eyes and kidneys. Control of cardio-metabolic risk factors (for example, blood glucose levels, blood pressure) can reduce the risk or slow the progression of diabetes-related complications.



Weight-loss is an important part of T2D management and can result in improved cardiometabolic risk factors and an associated decreased risk of T2D-related complications. While metabolic surgery is not currently part of the treatment pathway in Ireland, numerous diabetes and obesity organisations recommend that metabolic surgery – defined here as the use of bariatric surgery procedures with the intention of treating comorbid T2D and obesity – should be an accepted treatment option for people with comorbid T2D and obesity.

This research was carried out in accordance with HIQA’s guidelines for the conduct of HTA. In summary:

• The Terms of Reference of the HTA were agreed between HIQA and the Clinical Leads for the National Clinical Programmes for Diabetes and Obesity.
• An Expert Advisory Group was convened by HIQA to inform the assessment with representation from the National Clinical Programme for Diabetes, the National Clinical Programme for Diabetes, the National Clinical Programme for Surgery, the Irish College of General Practitioners (ICGP), clinicians with specialist expertise in diabetes and metabolic disease, methodological experts and relevant patient advocacy groups.
• The epidemiology of T2D and obesity in Ireland was assessed.
• A systematic review and meta-analysis of randomised controlled trials (RCTs) was carried out to summarise the best available evidence on the effectiveness and safety of metabolic surgery compared with best medical care or another metabolic surgery.
• A systematic review of cost-effectiveness was undertaken to summarise the international evidence on the cost-effectiveness of metabolic surgery compared with best medical care.
• An economic model was developed to estimate the cost-effectiveness and incremental budget impact associated with the proposed introduction of a metabolic surgery programme in Ireland.
• Finally, the organisational and ethical implications associated with the proposed introduction of the programme were considered.
• The draft report was reviewed by the Expert Advisory Group. A final draft report was submitted to the Board of HIQA for approval. Following its approval, the completed assessment was submitted to the Minister for Health and the HSE as advice.

• In patients with comorbid type 2 diabetes and obesity, the current clinical evidence suggests that metabolic surgery is safe, and is more effective than medical care in producing weight loss and improvements in glycaemic control. Metabolic surgery would likely result in a reduced risk of T2D-related complications and a reduction in health service utilisation over the longer term.
• Even based on conservative assumptions, a metabolic surgery programme provided as part of the T2D clinical care pathway would be an efficient and highly cost-effective use of healthcare resources relative to best medical care.
• The incremental budget impact was estimated at €7.4 million to provide 1,000 surgeries and follow-up care over five years. While an annual cohort of 200 patients was assumed, the budget impact would be directly proportional to the number of patients undergoing surgery.
• In the event that metabolic surgery is provided, it should be in the context of a programme including end-to-end care, from referral, pre-operative assessment, the acute surgical care episode through to long-term follow-up. To avoid existing surgical care being displaced, additional staff would be required.
• The success of a metabolic surgery programme would be dependent on the integration of patient management between primary and secondary care. Development of care pathways that include linkage to hospital and community services would be necessary to support GPs in providing long-term follow-up to these patients.
• The epidemiology of comorbid T2D and obesity in Ireland is not known with certainty due to the absence of up-to-date, nationally-representative data. Consideration should be given to the establishment of a national diabetes registry to support healthcare service planning in response to epidemiological trends.