Results of a Markov model analysis to assess the cost-effectiveness of a single tablet of fixed-dose amlodipine and atorvastatin for the primary prevention of cardiovascular disease in Korea

Abstract

Background: In Korea, the treatment of hypertension and dyslipidemia constitutes an important strategy for the prevention of cardiovascular disease (CVD).

Objective: This study sought to investigate the cost-effectiveness (from the Korean health care system perspective) of prescribing a proprietary formulation single-tablet fixed-dose combination of amlodipine and atorvastatin (at weighted mean doses of 5 mg and 10.25 mg, respectively) to all eligible patients aged > or = 45 years for the primary prevention of CVD (ie, coronary heart disease and ischemic stroke) in Korea, compared with currently observed patterns of blood-pressure and lipid-lowering medication prescription and use.

Methods: A Markov model was developed with 4 health states: alive without CVD, alive with CVD, dead from CVD, and dead from non-CVD causes. The model population comprised 244 Koreans aged >/=45 years from the 2005 Korean National Health and Nutrition Examination Survey (KNHNES) without a history of myocardial infarction (MI) or stroke who met current criteria for both blood-pressure and lipid-lowering treatment. From a 2008 baseline, follow-up was simulated for 40 years. Cardiovascular risk was estimated for each subject individually using a multivariate, Asian population-specific equation, and updated with ongoing cycles. Decision analysis compared the effects of prescribing the fixed-dose combination to all subjects versus currently observed patterns of treatment. Data regarding the blood-pressure and lipid-lowering efficacies of combination therapy were drawn from the Respond trial. Costs of the fixed-dose combination tablet and CVD were sourced from pharmaceutical pricing lists and Korean Health Insurance Review and Assessment Services estimates, respectively. Utility values for CVD were obtained from a large Korean utility study.

Results: In the model, of the 244 treatment-eligible subjects, 126 (51.6%) and 13 (5.3%) were taking blood-pressure and lipid-lowering therapy, respectively. Use of single-tablet fixed-dose combination amlodipine and atorvastatin by all subjects was associated with estimated incremental cost-effectiveness ratios of 7,773,063 Korean won (KRW) per quality-adjusted life-year gained and 10,378,230 KRW per overall life-year gained (1300 KRW approximately US $1). Sensitivity and uncertainty analyses indicated these results to be robust.

Conclusions: In this model, based on data from the 2005 KNHNES, hypertension and dyslipidemia were undertreated among Koreans aged > or = 45 years without a history of MI or stroke. The administration of single-tablet fixed-dose combination amlodipine and atorvastatin to all such individuals was likely to represent a cost-effective means of preventing first-onset CVD (ie, coronary heart disease and ischemic stroke) in this subgroup, compared with current patterns of treatment.