Cost-effectiveness of Initiating an Insulin Pump in T1D Adults Using Continuous Glucose Monitoring Compared with Multiple Daily Insulin Injections: The DIAMOND Randomized Trial

Abstract

Background: The economic impact of both continuous glucose monitoring (CGM) and insulin pumps (continuous subcutaneous insulin infusion (CSII)) in Type 1 diabetes (T1D) have been evaluated separately. However, the cost-effectiveness of adding CSII to existing CGM users has not yet been assessed. Objective: To evaluate the societal cost-effectiveness of CSII versus continuing multiple daily injections (MDI) in adults with T1D already using CGM. Methods: In the second phase of the DIAMOND trial, 75 adults using CGM were randomized to either CGM+CSII or CGM+MDI (control) and surveyed at baseline and 28 weeks. We performed within-trial and lifetime cost-effectiveness analyses (CEAs) and estimated lifetime costs and quality-adjusted life years (QALYs) via a modified Sheffield T1D model. Results: Within the trial, the CGM+CSII group had a significant reduction in quality of life from baseline (−0.02 ± 0.05 difference in difference (DiD)), compared to controls. Total per-person 28-week costs were $8,272 (CGM+CSII) vs $5,623 (CGM+MDI); the difference in costs was primarily attributable to pump use ($2,644). Pump users reduced insulin intake (−12.8 units DiD), but increased use of daily number of test strips (+1.2 DiD). Pump users also increased time with glucose in range 70–180 mg/dL, but had higher HbA1c (+0.13 DiD) and more non-severe hypoglycemic events. In the lifetime CEA, CGM+CSII would increase total costs by $112,045 DiD, decrease QALYs by 0.71, and life expectancy by 0.48 years. Conclusions: Based on this single trial, initiating an insulin pump in adults with T1D already using CGM was associated with higher costs and reduced quality of life. Additional evidence regarding the clinical effects of adopting combinations of new technologies from trials and real-world populations are needed to confirm these findings.

Glycemic Outcomes in Adults With T1D Are Impacted More by Continuous Glucose Monitoring Than by Insulin Delivery Method: 3 Years of Follow-Up From the COMISAIR Study

“…Importantly, our findings demonstrate that the use of rtCGM with MDI can be considered an equivalent but more cost-effective treatment alternative to sensor-augmented insulin pumps for many individuals with T1D. For example, in a recent analysis of the Multiple Daily Injections and Continuous Glucose Monitoring in Diabetes (DIAMOND) trial (8), Skandari and colleagues (27) found that among rtCGM1CSII participants, the total per-person 28-week costs were $8,272 vs. $5,623 among rtCGM1MDI users; the difference was primarily attributed to CSII use. The increasing focus on reducing costs while improving outcomes may impact reimbursement decisions regarding current and future sensor-augmented insulin pump systems.…”

RT‐CGM in conjunction with CSII vs MDI in optimizing glycaemic control in T1DM: Systemic review and meta‐analysis

“…Nonetheless, Wan et al, 19 which was a cost‐effective study of the DIAMOND trial, 15 showed that within‐trial cost‐effectiveness analysis (CEA) when adding CSII to CGM users increased costs with 28‐week costs were $8272 (RT‐CGM+CSII) vs $5623 (RT‐ CGM+MDI), with the difference in costs being attributed to pump use ($2644). In addition, it reduced quality of life, worsened glucose control (higher HbA1c), caused overall clinical harm and increased non‐severe hypoglycaemic events (NSHEs), which was defined as the detection of a glucose value <3.0 mmol/l (<54 mg/dl) for at least 20 consecutive minutes.…”

The improved survival rate and cost-effectiveness of a 7-day continuous subcutaneous insulin infusion set

“…The use of CSII systems has resulted in decreased mortality rates and improved quality of life, especially when used in conjunction with rapid-acting insulins. Additionally, users who switch over from multiple daily injections (MDI) to CSII often experience a 20-26% decrease in insulin use [52][53][54]. However, the cost of diabetes care has also risen dramatically within the last few decades, even to the point of posing as an inaccessible barrier to people with diabetes [55,56].…”