Aims: To estimate the cost effectiveness of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) for patients using insulin pumps.
Methods: We constructed a Markov model to estimate the costs and outcomes for patients with insulin-dependent diabetes (IDDM) treated with CSII using an insulin pump compared with MDI. Key parameters were obtained from the published scientific literature. The primary outcome was quality-adjusted life years (QALYs). Monte Carlo simulations were undertaken for 10 000 hypothetical patients over 8 years of monthly cycles (the expected life of a pump).
Results: Over an 8-year period an average patient could expect to gain 0.48 [standard deviation (sd) 0.20] QALYs using CSII compared with MDI. The additional cost over 8 years for this gain was pounds 5462 (sd pounds 897). The incremental cost per QALY was pounds 11,461 (sd pounds 3656). CSII was most cost-effective in patients who had more than two severe hypoglycaemic events per year and who required admission to hospital at least once every year. Cases where CSII might be not economically viable are cases where diabetes is well controlled with few severe hypoglycaemic events. Results were most sensitive to the number of hypoglycaemic events per patient and the utility weights used to estimate QALYs.
Conclusion: CSII is a worthwhile investment when targeted to those who might benefit most.