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

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-naïve 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.