Cost-Effectiveness Study To Evaluate Insulin Glargine Compared With NPH Insulin In Patients With Type 2 Diabetes Uncontrolled With Oral Anti-Diabetic Agents In Hong Kong

Abstract

Insulin glargine is superior to neutral protamine Hagedorn (NPH) insulin in reducing blood glucose and has lower risk of hypoglycaemia. Due to higher acquisition costs, use of insulin glargine remains second-line in Hong Kong. We conducted a cost-effectiveness analysis of insulin glargine compared with NPH insulin by applying local patient and cost data to a published diabetes outcome model. The IMS CORE Diabetes Model Version 9.0 was used for projection of complication and economic outcomes. The model was populated with clinical data from the Hong Kong Diabetes Registry. We selected patients with type 2 diabetes, on non-insulin anti-diabetic drugs and were uncontrolled with HbA1c ≥7.5%. Efficacy of intervention with respect to reduction of HbA1c and rates of hypoglycaemia were based on results of Lantus Evaluation in Asian Diabetics study, which compared insulin glargine and NPH insulin in an Asian population. Costs of insulins and diabetes complications were assembled using cost data listed in Hospital Authority Gazette. Costs and outcomes were discounted at 3%/year. A simulation period of 50 years was applied. The simulation cohort had mean age 57.3±13.1years and HbA1c 8.9±1.5%, between 2-8% had established cardiovascular disease, and 23-29% had microvascular complications. Over 50-year simulation, total costs of treating diabetes which included costs related to diabetes complications were modestly higher with insulin glargine (HKD 708,250 [USD 91,142]) than NPH insulin (HKD 707,289 [USD 91,018]). Treatment with insulin glargine led to a gain in life year of 0.017 years/patient and in quality-adjusted life year (QALY) of 0.025 years/patient compared with treatment with NPH insulin. The incremental cost-effectiveness ratio of insulin glargine over NPH insulin was HKD 38,788 (USD 4,991)/QALY, which was below the current gross domestic product per capita in Hong Kong. Applying WHO threshold of cost-effectiveness, insulin glargine was highly cost-effective relative to NPH insulin.