Cost-effectiveness of switching to biphasic insulin aspart in poorly-controlled type 2 diabetes patients in China

Abstract

Type 2 diabetes is an increasing problem in China, yet there is a paucity of data regarding the cost-effectiveness of pharmacological interventions in the Chinese setting. Previous data were obtained from PRESENT (Physicians' Routine Evaluation of Safety and Efficacy of NovoMix 30 Therapy), a multi-country, single-arm, observational study where type 2 diabetes patients poorly controlled with biphasic human insulin (BHI) were converted to biphasic insulin aspart 30 (BIAsp30); the Chinese subgroup experienced an improvement in HbA(1c) and a reduction in hypoglycaemic events. A published and validated computer simulation model of diabetes (the CORE Diabetes Model) was used to estimate the long-term clinical and cost consequences of switching to BIAsp30 from BHI in the Chinese setting. Treatment effects and patient characteristics were derived from PRESENT and country-specific published sources. Primary research was performed to ascertain patient management practices and diabetes-related complication costs. Risks of modelled complications were derived from landmark clinical trials and epidemiological studies. Costs and clinical projections were made over patient lifetimes from a third-party payer perspective and discounted at 3% annually. Extensive sensitivity analyses were performed. Conversion to BIAsp30 from BHI was projected to improve discounted life expectancy by 0.38 years per patient (9.91 vs 9.53 years) and quality-adjusted life expectancy by 0.91 quality-adjusted life years (QALYs) per patient (6.32 vs 5.41 QALYs). Conversion to BIAsp30 was associated with increased direct medical costs of Chinese Yuan (CNY) 1751 per patient, due to higher pharmacy and management costs (CNY +19,007), offset by reduced diabetes-related complication costs (CNY -17,254) over patient lifetimes. BIAsp30 was associated with an incremental cost-effectiveness ratio of CNY 1926 per QALY gained. BIAsp30 was projected to substantially improve clinical outcomes but was associated with increased lifetime medical costs. BIAsp30 would be considered cost-effective in China given a willingness-to-pay threshold of CNY 100,000 per QALY gained in type 2 diabetes patients poorly controlled on BHI.