A Study of time preference for money and health outcomes and application in health economic evaluation

Abstract

This dissertation purposed to investigate discount rates for both monetary and health outcomes in Thailand and evaluate the consequences of varying discount rates from recommended discount rates through a case study on economic evaluation. Furthermore, it aimed to examine the economic and clinical outcomes among patients with AS using the national health database to determine input parameters for an economic evaluation. The dissertation comprised 3 studies. Study I, an experimental study involved 1,202 participants who underwent individual interviews to ascertain discount rates. Participants were presented with monetary and health-related scenarios, such as air pollution and the Coronavirus Disease 2019 (COVID-19), and their indifference values were elicited using a choice-based method. This data was then used to calculate discount factors and estimate annual discount rates. The findings revealed a higher discount rate for monetary outcomes (6.2%) compared to health outcomes (1.3%), with health discount rates higher during the COVID-19 scenario (2.4%) than air pollution (0.7%). Study II, a database analysis was conducted using e-claim databased managed by the National Health Security Office to assess the economic burden, hospitalization rates, and in-hospital mortality among adult patients diagnosed with aortic stenosis (AS) in Thailand. Over an 8-year period (2015 to 2022), the study observed an significant increase in hospitalizations among individuals aged 60 to 79 (p<0.001), along with a rise in in-hospital mortality and treatment costs. Study III, an economic evaluation aimed to assess the cost-effectiveness of sutureless and rapid deployment aortic valve replacement (SUAVR) compared to conventional aortic valve replacement (CAVR) in Thailand. The base-case analysis indicated that SUAVR incurred higher lifetime costs (THB 1,733,355 vs. 1,220,643), while quality-adjusted life years (QALYs) were lower than CAVR (4.95 vs. 5.08 years), resulting in it being a dominated treatment strategy. However, when alternative discount rates were applied, both SUAVR and CAVR demonstrated lower lifetime costs and higher QALYs, suggesting potential long-term benefits and cost-effectiveness. In conclusion, this study highlighted the significance of setting a lower annual discount rate for health compared to money and underscored the importance of considering discount rates across various types of diseases. Additionally, these findings underscored the importance of considering differential discount rates for health and monetary outcomes in economic evaluations and the potential implications for the cost-effectiveness of healthcare interventions.