The Cost-Effectiveness of Continuous Glucose Monitoring in Type 1 Diabetes

OBJECTIVE

Continuous glucose monitoring (CGM) has been found to improve glucose control in type 1 diabetic patients. We estimated the cost-effectiveness of CGM versus standard glucose monitoring in type 1 diabetes.

RESEARCH DESIGN AND METHODS

This societal cost-effectiveness analysis (CEA) was conducted in trial populations in which CGM has produced a significant glycemic benefit (A1C ≥7.0% in a cohort of adults aged ≥25 years and A1C <7.0% in a cohort of all ages). Trial data were integrated into a simulation model of type 1 diabetes complications. The main outcome was the cost per quality-adjusted life-year (QALY) gained.

RESULTS

During the trials, CGM patients experienced an immediate quality-of-life benefit (A1C ≥7.0% cohort: 0.70 quality-adjusted life-weeks [QALWs], P = 0.49; A1C <7.0% cohort: 1.39 QALWs, P = 0.04) and improved glucose control. In the long-term, CEA for the A1C ≥7.0% cohort, CGM was projected to reduce the lifetime probability of microvascular complications; the average gain in QALYs was 0.60. The incremental cost-effectiveness ratio (ICER) was $98,679/QALY (95% CI −60,000 [fourth quadrant] to −87,000 [second quadrant]). For the A1C <7.0% cohort, the average gain in QALYs was 1.11. The ICER was $78,943/QALY (15,000 [first quadrant] to −291,000 [second quadrant]). If the benefit of CGM had been limited to the long-term effects of improved glucose control, the ICER would exceed $700,000/QALY. If test strip use had been two per day with CGM long term the ICER for CGM would improve significantly.

CONCLUSIONS

Long-term projections indicate that CGM is cost-effective among type 1 diabetic patients at the $100,000/QALY threshold, although considerable uncertainty surrounds these estimates.The Diabetes Control and Complication Trial (DCCT) established the clinical benefits of intensive glucose control in type 1 diabetes (1). Despite the availability of insulin pumps and insulin analogues, achieving optimal glucose control, while avoiding hypoglycemia, continues to be a significant challenge for patients.An important component of glucose control is glucose monitoring. Conventional self-glucose monitoring permits patients to periodically measure capillary glucose. This leaves patients unaware of postprandial hyperglycemia and asymptomatic nocturnal hypoglycemia (2). Newer continuous glucose monitoring (CGM) technology, which measures glucose levels in subcutaneous tissue, has the potential to overcome these challenges and increase the likelihood that patients with diabetes can achieve and maintain optimal glucose control without symptomatic hypoglycemia. While there are potential advantages of CGM, the technology does have some disadvantages, including discomfort from the probe, ongoing use of conventional monitoring, potential overestimation of the frequency of overnight low glucose levels, and high costs (3).Recently, parallel multicenter trials comparing CGM with conventional self-glucose monitoring alone were conducted in patients with A1C ≥7.0% (A1C ≥7.0% cohort) and in patients with A1C <7.0% (A1C <7.0% cohort) (4). In the A1C ≥7.0% cohort, CGM was found to significantly reduce average A1C levels (−0.53 [95% CI −0.71 to −0.35], P < 0.001) in adults (aged ≥25 years) (5). In the A1C <7.0% cohort, CGM helped intervention patients maintain their A1C at 6.5%, while control patients experienced an increase in A1C of 0.3% (6). The purpose of this study is to evaluate the cost-effectiveness of CGM technology compared with standard glucose monitoring in the type 1 diabetic patients from the societal perspective.