Insulin therapy in type 2 diabetes patients failing oral agents: cost‐effectiveness of biphasic insulin aspart 70/30 vs. insulin glargine in the US*

Abstract

Objectives: To project the long-term clinical and economic outcomes of treatment with biphasic insulin aspart 30 (BIAsp 70/30, 30% soluble and 70% protaminated insulin aspart) vs. insulin glargine in insulin-naive type 2 diabetes patients failing to achieve glycemic control with oral antidiabetic agents alone (OADs). Methods: Baseline patient characteristics and treatment effect data from the recent 'INITIATE' clinical trial served as input to a peer-reviewed, validated Markov/Monte-Carlo simulation model. INITIATE demonstrated improvements in HbA1c favouring BIAsp 70/30 vs. glargine (-0.43%; p < 0.005) and greater efficacy in reaching glycaemic targets among patients poorly controlled on OAD therapy. Effects on life expectancy (LE), quality-adjusted life expectancy (QALE), cumulative incidence of diabetes-related complications and direct medical costs (2004 USD) were projected over 35 years. Clinical outcomes and costs were discounted at a rate of 3.0% per annum. Sensitivity analyses were performed. Results: Improvements in glycaemic control were projected to lead to gains in LE (0.19 +/- 0.24 years) and QALE (0.19 +/- 0.17 years) favouring BIAsp 70/30 vs. glargine. Treatment with BIAsp 70/30 was also associated with reductions in the cumulative incidences of diabetes-related complications, notably in renal and retinal conditions. The incremental cost-effectiveness ratio was $46 533 per quality-adjusted life year gained with BIAsp 70/30 vs. glargine (for patients with baseline HbA1c >= 8.5%, it was $34 916). Total lifetime costs were compared to efficacy rates in both arms as a ratio, which revealed that the lifetime cost per patient treated successfully to target HbA1c levels of < 7.0% and <= 6.5% were $80 523 and $93 242 lower with BIAsp 70/30 than with glargine, respectively. Conclusions: Long-term treatment with BIAsp 70/30 was projected to be cost-effective for patients with type 2 diabetes insufficiently controlled on OADs alone compared to glargine. Treatment with BIAsp 70/30 was estimated to represent an appropriate investment of healthcare dollars in the management of type 2 diabetes.