OBJECTIVES : In Thailand, access to atorvastatin is largely limited to patients with previous cardiovascular (CV) events given its inclusion in the Thai reimbursement list for secondary prevention. This study aims to estimate the short-term cost-effectiveness (CE) of atorvastatin compared to simvastatin in prevention of CV events in both primary and secondary prevention settings from the societal perspective in Thailand.

METHODS : A CE model was developed in Microsoft Excel with a time horizon of 2 years. The model included 4 defined patient populations: (1) diabetes mellitus; (2) multiple risk factors; (3) coronary heart disease; and (4) acute coronary syndrome. The CV event risk (myocardial infarctions (MI), stroke, and revascularizations), mortality, and treatment adherence data were obtained from pivotal trials. Epidemiology, direct medical costs, drug costs and wage data were obtained from the literature and publicly available sources. Outcomes estimated were number of CV events prevented, direct and indirect cost savings, and cost per CV event avoided with the use of atorvastatin compared to simvastatin. Costs were inflated to 2020 Thai Baht. One-way sensitivity analysis (OWSA) was conducted to test the robustness of the results.

RESULTS : Fifty-five million Thai adults were considered in the model among which 10 million were deemed eligible for using statins. An incremental CE ratio could not be calculated because compared to simvastatin, atorvastatin not only prevented 183,570 CV events (85,313 MIs, 49,637 strokes, and 48,620 revascularizations) but also led to net cost savings of ฿1,440 million (direct and indirect cost savings of ฿17,955 million and ฿51,205 million, respectively, and additional drug cost of ฿67,720 million). OWSA showed that results were mainly driven by atorvastatin drug cost, mortality rate, and productivity loss due to premature deaths.

CONCLUSIONS : Atorvastatin is cost-effective compared to simvastatin in prevention of CV events from Thailand societal perspective.