Cost-Effectiveness of Insulin Glargine Versus NPH Insulin for the Treatment of Type 1 and Type 2 Diabetes Modeling the Interaction between Hypoglycemia and Glycemic Control in Switzerland

RESULTS:: The study objective was to model the cost-effectiveness of insulin glargine (glargine) compared to NPH insulin (NPH) in patients with type 1 (T1D) and type 2 (T2D) diabetes considering the interaction between hypoglycemia and glycemic control (HbA1c). Two validated distinct discrete event simulation models for T1D and T2D using evidence from DCCT and UKPDS, respectively, were applied to predict incidence of hypoglycemic, micro- and macrovascular events, life expectancy, quality-adjusted life years and direct medical costs in patients on glargine or NPH. Both models were populated with published Swiss patient characteristics. Baseline risks and % reductions of symptomatic, nocturnal and severe hypoglycemic events (RR) as well as utility decrements of micro- and macrovascular events and the hypoglycemia fear score were derived from literature. Costs of severe hypoglycemia, micro- and macrovascular events, applied from literature or guideline-projected resource-use estimation, were valued with Swiss official prices or tariffs and were expressed in 2006 CHF. Simulations were run with 1000 patients/cohort over a time horizon of 40 years. Costs and effects were discounted at 3.5%/year. Incremental cost effectiveness ratios (ICER) were expressed as cost per quality adjusted life year (QALY) and per life year gained (LYG). Univariate sensitivity analyses were performed. Over a lifetime horizon (40 years), glargine was associated with additional life expectancy (0.059) in T1D and T2D (0.05) as well as an improvement in QALYs of 0.238 in T1D and of 0.098 in T2D compared to NPH. In T1D, savings of CHF 1,476 turned glargine into the dominant strategy. In T2D, incremental costs of CHF 2,578 resulted in an ICER of CHF 51,100/LYG and CHF 26,271/QALY gained. ICERs were most sensitive to changes in time horizon, utility decrements and RR of hypoglycemia. It is concluded that modeling the interaction between hypoglycemia and glycemic control glargine versus NPH seems to be the dominant strategy in T1D and cost effective compared to accepted ICER thresholds (less than CHF 60,000/QALY) in T2D in Switzerland.