Abstract
Background: There is a growing variety of pharmacogenetic tests that can be used to predict how someone would respond to different drugs. This will result in increased health care costs, compared to standard treatment without pre-treatment pharmacogenetic testing. However, healthcare resource and budget are limited. Consequently, it is important to prioritize pharmacogenetic testing and select pharmacogenetic testing in Thailand in order to be suitable to the Thai context and can be used for economic evaluation in the future. Objectives: This study aimed to prioritize and select pharmacogenetic testing in Thailand, perform economic evolution of selected pharmacogenetic testing, and 3) evaluate budget impact of pharmacogenomics testing, if included in the benefit package under the Universal Health Coverage (UHC). Methods: Prioritization and selection method for drug-related pharmacogenetic tests (gene-drug pairs) that are important in the Thai population were used to select pharmacogenetic testing for evaluating their cost-effectiveness through reviewing the literatures and recommendations from pharmacogenetic experts to be used as scoring criteria and selection. Apart from this, the cost-utility and budget impact analyses of HLA-B*13:01 testing before initiation of co-trimoxazole treatment to prevent DRESS and dapsone treatment to avoid SCAR compared to no testing were undertaken using a decision tree and Markov model. Results: From the prioritization of gene-drug pairs according to the prioritization criteria, in HLAs group, it was found that gene-drug HLA-B*15:02–phenytoin, HLA-B*57:01-abacavir, HLA-B*13:01-co-trimoxazole and HLA-B*13:01-dapsone should be considered for economic evaluation in Thailand. In non-HLA group, gene-drug CYP2B6- efavirenz, SLCO1B1-simvastatin และ NAT2-ethambutol, isoniazid, pyrazinamide, rifampin should be selected as a candidate for economic evaluation in Thailand. Results of economic evaluation showed that HLA-B*13:01 testing before initiation of co-trimoxazole treatment to prevent DRESS and dapsone treatment to avoid SCAR was not cost-effective, compared with the group without pharmacogenetic testing. The provision of HLA-B*13:01 testing resulted in the budget impact of 2,246,000 baht per year. Conclusions: The results of the study of the prioritization of gene-drug pairs can be used to consider the selection of gene-drug pairs for future economic evaluation in Thailand. HLA-B*13:01 testing prior to initiation of co-trimoxazole and dapsone was not cost-effective and therefore is not proposed to be included in the UHC Benefit Package.
