Objectives: The aim of this study was to project the long-term costs and outcomes of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) in patients with Type 1 diabetes in the UK.
Methods: The CORE Diabetes Model is a peer-reviewed, validated model which employs standard Markov/Monte Carlo simulation techniques to describe the long-term incidence and progression of diabetes-related complications. It was used to simulate disease progression in a cohort of patients with baseline characteristics taken from published UK studies (mean age 26 years, duration of diabetes 12 years, mean HbA1c 8.68%). Direct costs for 2003 were calculated from a third-party payer perspective. Discount rates of 3.0% per annum were applied to costs and clinical outcomes.
Results: Treatment with CSII was associated with an improvement in mean quality adjusted life expectancy (QALE) of 0.76 +/- 0.19 years compared with MDI (12.03 +/- 0.15 vs. 11.27 +/- 0.14 years). Mean direct lifetime costs were pounds 19,407 +/- 1727 higher with CSII treatment compared with MDI (pounds 80,511 +/- 1257 vs. pounds 61,104 +/- 1249). This produced an incremental cost-effectiveness ratio (ICER) of pounds 25,648 per quality-adjusted life year (QALY) gained with CSII vs. MDI. The results were most sensitive to variation in hypoglycaemia rates and altering improvements in HbA1c associated with CSII therapy compared with MDI.
Conclusions: Improvements in glycaemic control associated with CSII over MDI led to improved QALE owing to reduced incidence of diabetes-related complications. CSII was associated with an ICER of pounds 25,648 per QALY gained vs. MDI, representing good value for money by current standards in the UK.