Cost-Utility Analysis of Oral Anticoagulants for Nonvalvular Atrial Fibrillation Patients at the Police General Hospital,Bangkok, Thailand

Purpose

The genetic polymorphism was one of the major considerations for adjusting doses of warfarin in Thai individuals. As a result, new oral anticoagulants (NOACs) were introduced to achieve therapeutic goals in stroke prevention in atrial fibrillation (SPAF) patients. However, a cost-utility analysis in a population-specific model was lacking in Thailand. This study was performed to determine which NOACs yielded population-specific, cost-effective results for SPAF compared with warfarin from both governmental and societal perspectives in Thailand.

Methods

A simplified Markov health state model was constructed to calculate the lifetime cost, life-years saved, and quality-adjusted life-years (QALYs) gained. Asia-specific clinical event parameters were defined from systematic searches of PubMed. Cost and utility input was obtained from hospital based data collection.

Findings

Although NOACs produced more life-years saved and QALYs gained resulting from the base-case versus warfarin, the lifetime costs of new alternatives increased to >1.4 times the comparative cost of warfarin. This caused an incremental cost-effective ratio that exceeded Thailand’s cost-effectiveness threshold. The probabilistic sensitivity analysis denoted the robustness of our model and revealed that dose-adjusted warfarin was the most cost-effective option in >99% of iterations. NOACs produced cost-effective results when the medication unit cost was decreased by at least 85%.

Implications

According to the results of this first cost-utility analysis in Thailand, warfarin is still the most cost-effective medication for SPAF from any perspective in Thailand at the threshold recommended by our health technology assessment guidelines.