Costs per DALYs Averted of Quadrivalent Influenza Vaccine versus Trivalent Influenza Vaccine in Elderly Population in Thailand

Abstract

Objective: Influenza is an infection of the respiratory system with a high annual incident rate. Influenza vaccinecan reduce the severity of influenza and prevent transmission of the virus. Influenza vaccines in Thailand are theTrivalent Influenza Vaccine (TIV) and the Quadrivalent Influenza Vaccine (QIV). The cost and the effectiveness ofthe QIV in preventing transmission of the virus are greater than the TIV. Until now, no studies have been conductedto compare the economic impact of using QIV or TIV. This study aimed to evaluate the economic effects of usingQIV versus TIV in Thai populations age 60 years and over.Materials and Methods: The study was carried out from a societal perspective for cost per DALYs averted. A decisiontree model was used to analyse the costs and DALYs averted of Thais after they received the vaccine.Results: In a period of one year, it was found that in Thais age 60 years and over, the total cost of TIV was 2,445.19baht with 0.0094 DALYs and total cost of the QIV was 2,629.28 baht with 0.0082 DALYs and the incremental costeffectivenessratio (ICER) of the QIV was 158,489.24 baht per DALYs averted. The acceptability curves demonstratedthat the probability of QIV being cost-effective was 95% of the willingness to pay, being 1.2 times the Thai grossnational income per capita.Conclusion: Therefore, in Thai people age over 60 years and over, QIV is more cost-effective than TIV. The resultsof this study can be used by policymakers to help inform their decisions about which influenza vaccine is morecost-effective.