Diabetes complications are associated with significant morbidity and mortality for individuals and can place a considerable economic burden on healthcare systems and society. Intensive treatment is required to reduce the risk of developing complications. Monitoring glucose levels is an integral part of the management plan for individuals with diagnosed type 1 diabetes mellitus on intensive insulin therapy, as they are at risk of hypoglycaemia (when blood glucose is too low) and hyperglycaemia (when blood glucose is too high). Glucose readings are important to guide insulin treatment, maintain optimal glucose control, and reduce the occurrence of complications of diabetes. In common use since the 1980s, the standard method of glucose monitoring has been self-monitoring of blood glucose (SMBG) using capillary blood glucose. SMBG is commonly done through intermittent use of a finger-prick test (although blood may be drawn from other sites) with a lancet, using testing strips and electronic blood glucose meters to determine blood glucose concentration.

Continuous glucose monitoring (CGM) systems provide an alternative to SMBG, by measuring glucose levels in the interstitial fluid (a thin layer of fluid around the cells). CGM systems can provide current glucose levels as well as trend data (increasing, decreasing, stable, rate of change).

Information on glucose levels is used by the person with diabetes to inform decisions about their insulin regimen (such as schedule or dose) or interventions to minimise the risk of high and low glucose levels. CGM enables people with diabetes to monitor their blood glucose levels without the need for finger pricking.

The HSE currently reimburses several CGM systems, but access rules differ by system and individual’s age, and access can be limited by local health area budgets. 

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

• The terms of reference for the HTA were agreed between HIQA and the Health Service Executive. 
• An expert advisory group (EAG) comprising representation from key stakeholders was convened to inform and guide the process, and to provide expert advice and information. 
• The epidemiology of T1DM in Ireland was described.
• The technologies, that is, the CGM systems authorised for use in Ireland, were described. 
• A targeted literature review was conducted to assess the effectiveness of CGM improving blood glucose outcomes. 
• A targeted review of economic evaluations was conducted to identify the most up to date international evidence on cost-effectiveness of CGM system for T1DM.
• A budget impact analysis focusing on the reimbursement of CGM devices to adults with T1DM in Ireland was undertaken.
• A review of UK guidelines for CGM was also undertaken. 
• The draft HTA report was reviewed by the EAG. All feedback was reviewed and incorporated as appropriate. 
• A final draft report was submitted to HIQA’s Executive Management Team for approval. Following its approval, the completed assessment was submitted to the Health Service Executive as advice.

• Continuous glucose monitoring (CGM) is an alternative to self-monitoring using capillary blood glucose (SMBG) in individuals with diabetes. CGM is a sensor-based technology that reduces the need for finger-prick testing and provides additional information about trends in glucose levels. There are two types of CGM: intermittently scanned (isCGM) and real-time (rtCGM). 
• The current Irish National Clinical Guideline for type 1 diabetes mellitus (T1DM) is based on a contextualisation of the corresponding 2015 guideline from NICE. In 2022, the NICE guideline was updated to recommend CGM for all adults with T1DM. Given this update, the Irish National Clinical Guideline should be revisited.
• There is some evidence to suggest that CGM improves glycaemic outcomes compared with SMBG, particularly time in range. There is limited head-to-head evidence to distinguish between CGM types in terms of effectiveness.
• In Ireland, routes of access to the technologies approved for reimbursement differ by CGM system type and component. Current reimbursement protocols mean that access to isCGM is highly restricted for those aged over 21 years when first seeking access. However, reimbursed access to rtCGM is not restricted to the same degree. 
• Annual HSE expenditure on CGM increased from €0.9 million in 2016 to €30 million in 2022; over 90% of the expenditure in 2022 related to rtCGM. There are differences in costs in rtCGM systems, but currently all reimbursed rtCGM systems are considerably more expensive than the reimbursed isCGM system. 
• The different pathways to reimbursed access to rtCGM and isCGM, and the substantial difference in costs between technologies have considerable implications for the cost effectiveness and overall budget impact of CGM for the HSE.
• There is substantial uncertainty regarding the prevalence of T1DM in adults in Ireland. Considering a potential total adult population with T1DM of 24,480:
  • If uptake increases to 85.5% (that is an additional 35% access CGM), this would cost the HSE an additional €24.8 million over the next five years if all new uptake relates to isCGM and €84.4 million if all new uptake relates to rtCGM. 
  • If uptake increases at a faster rate or were to be closer to full coverage then the budget impact would be considerably higher.
  • These costs are in addition to existing annual expenditure on CGM.
  • The BIA assumes that once initiated on a particular system, individuals remain on the same CGM system for the duration of the five year period. It also does not account for those who are currently using CGM, switching systems. 
  • Switching to an economically advantageous system, when clinically appropriate to do so, may result in cost savings for the HSE.
• Consideration should be given to the:
  • Provision of CGM in the context of the existing model of care for people with T1DM which includes oversight by specialist diabetes services and empowerment of the person with diabetes through access to structured diabetes self-management education.
  • Establishment of a single managed access programme for all CGM systems for all individuals with T1DM regardless of age. Such a system would need clearly defined criteria for access.
  • Establishment of a national registry for people with diabetes, within the context of ongoing national and European policy and legislative developments regarding health information, to support healthcare service planning for this population.