A Cost-Effectiveness Analysis of Continuous Subcutaneous Insulin Injection versus Multiple Daily Injections in Type 1 Diabetes Patients: A Third-Party US Payer Perspective

Objective: To estimate the long-term cost-effectiveness of using continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) of insulin in adult and child/young adult type 1 diabetes mellitus (T1DM) patients from a third-party payer perspective in the United States. Method: A previously validated health economic model was used to determine the incremental cost-effectiveness ratio (ICER) of CSII compared with MDI using published clinical and cost data. The primary input variable was change in HbA(1c), and was assumed to be an improvement of -0.9% to -1.2% for CSII compared with MDI for child/young adult and adults, respectively. A series of Markov constructs simulated the progression of diabetes-related complications. Results: CSII was associated with an improvement in quality-adjusted life-years (QALYs) gained of 1.061 versus MDI for adults and 0.799 versus MDI for children/young adults. ICERs were $16,992 and $27,195 per QALY gained for CSII versus MDI in adults and children/young adults, respectively. Improved glycemic control from CSII led to a lower incidence of diabetes complications, with the most significant reduction in proliferative diabetic retinopathy (PDR), end stage renal disease (ESRD), and peripheral vascular disease (PVD). The number needed to treat (NNT) for PDR was nine patients, suggesting that only nine patients need to be treated with CSII to avoid one case of PDR. The NNT for ESRD and PVD was 19 and 41, respectively. Conclusions: Setting the willingness to pay at $50,000/QALY, the analysis demonstrated that CSII is a cost-effective option for patients with T1DM in the United States.