Continuous Monitoring of Glucose for Type 1 Diabetes: A Health Technology Assessment

Abstract

Background: Type 1 diabetes is a condition in which the pancreas produces little or no insulin. People with type 1 diabetes must manage their blood glucose levels by monitoring the amount of glucose in their blood and administering appropriate amounts of insulin via injection or an insulin pump. Continuous glucose monitoring may be beneficial compared to self-monitoring of blood glucose using a blood glucose meter. It provides insight into a person's blood glucose levels on a continuous basis, and can identify whether blood glucose levels are trending up or down.

Methods: We conducted a health technology assessment, which included an evaluation of clinical benefit, value for money, and patient preferences related to continuous glucose monitoring. We compared continuous glucose monitoring with self-monitoring of blood glucose using a finger-prick and a blood glucose meter. We performed a systematic literature search for studies published since January 1, 2010. We created a Markov model projecting the lifetime horizon of adults with type 1 diabetes, and performed a budget impact analysis from the perspective of the health care payer. We also conducted interviews and focus group discussions with people who self-manage their type 1 diabetes or support the management of a child with type 1 diabetes.

Results: Twenty studies were included in the clinical evidence review. Compared with self-monitoring of blood glucose, continuous glucose monitoring improved the percentage of time patients spent in the target glycemic range by 9.6% (95% confidence interval 8.0-11.2) to 10.0% (95% confidence interval 6.75-13.25) and decreased the number of severe hypoglycemic events.Continuous glucose monitoring was associated with higher costs and small increases in health benefits (quality-adjusted life-years). Incremental cost-effectiveness ratios (ICERs) ranged from $592,206 to $1,108,812 per quality-adjusted life-year gained in analyses comparing four continuous glucose monitoring interventions to usual care. However, the uncertainty around the ICERs was large. The net budget impact of publicly funding continuous glucose monitoring assuming a 20% annual increase in adoption of continuous glucose monitoring would range from $8.5 million in year 1 to $16.2 million in year 5.Patient engagement surrounding the topic of continuous glucose monitoring was robust. Patients perceived that these devices provided important social, emotional, and medical and safety benefits in managing type 1 diabetes, especially in children.

Conclusions: Continuous glucose monitoring was more effective than self-monitoring of blood glucose in managing type 1 diabetes for some outcomes, such as time spent in the target glucose range and time spent outside the target glucose range (moderate certainty in this evidence). We were less certain that continuous glucose monitoring would reduce the number of severe hypoglycemic events. Compared with self-monitoring of blood glucose, the costs of continuous glucose monitoring were higher, with only small increases in health benefits. Publicly funding continuous glucose monitoring for the type 1 diabetes population in Ontario would result in additional costs to the health system over the next 5 years. Adult patients and parents of children with type 1 diabetes reported very positive experiences with continuous glucose monitoring. The high ongoing cost of continuous glucose monitoring devices was seen as the greatest barrier to their widespread use.

Figure 1:. PRISMA Flow Diagram—Clinical Search Strategy

Figure 2:. Changes in A1C from Baseline to End of Study

Figure 3:. PRISMA Flow Diagram—Economic Search Strategy

Figure 4:. Continuous Glucose Monitoring Versus Self-Monitoring of Blood Glucose—Long-Term Markov Model of Complications in Patients With Type 1 Diabetes^a

Figure 5:. One-Way Sensitivity Analysis: Continuous Glucose Monitoring With Multiple Daily Injections Versus Self-Monitoring of Blood Glucose With Multiple Daily Injections

Figure 6:. Continuous Glucose Monitoring—Current Use and Projection Scenarios in Ontario, 2018–2022

Figure A1:. Continuous Glucose Monitoring With Sensor-Augmented Pump Versus Self-Monitoring of Blood Glucose Plus Insulin Pump

Figure A2:. Continuous Glucose Monitoring Plus Insulin Pump Versus Self-Monitoring of Blood Glucose Plus Insulin Pump

Figure A3:. Continuous Glucose Monitoring With Sensor-Augmented Pump Versus Self-Monitoring of Blood Glucose With Multiple Daily Injections

Figure A4:. Cost-Effectiveness Acceptability Curves: Continuous Glucose Monitoring Interventions

Figure A5:. Call for Participation

Figure A6:. Interview Guide