Willingness to pay for the effect of SARS-CoV-2 antivirals in preventing COVID-19 transmission to others in the Japanese population.

Objective: This study aimed to investigate the willingness to pay (WTP) of the Japanese population for the transmission prevention function of SARS-CoV-2 antiviral treatments and identify the attributes associated with higher WTP.

Methods: A web-based survey (registration number: UMIN000054955) was conducted from May 17 to June 1, 2024, targeting a general population using a survey company panel. We aimed to obtain around 3,000 valid responses. Respondents were randomly divided into two groups: one assuming a COVID-19 infection (infection-assumed group) and the other without this assumption (non-infection-assumed group). WTP was assessed using an open-ended question format, asking how much they would be willing to pay out-of-pocket for a hypothetical antiviral drug that reduces the risk of transmitting COVID-19 to others by half. The survey also collected demographic information, COVID-19 related attributes, empathy levels using the Multidimensional Empathy Scale (MES), and health literacy using the Communicative and Critical Health Literacy scale. The mean WTP for COVID-19 treatment was calculated for all respondents and for the infection-assumed and non-infection-assumed groups. Subgroup analyses examined the effects of respondent attributes on WTP. A linear regression model with stepwise selection identified factors associated with WTP.

Results: Responses were obtained from 3,657 individuals, with 3,131 valid responses analyzed. The mean WTP among all respondents was JPY 3,205 (USD 20.85) (standard error: JPY 84 [USD 0.55]). The infection-assumed group showed a 21% higher WTP than the non-infection-assumed group (p < 0.001). Subgroup analyses indicated that WTP varied based on attributes such as co-residing children, occupation, empathy levels, and health literacy. Higher WTP was significantly associated with being aged 65 years and older, higher household income, absence of co-residing children, being a company employee, executive, or public servant, fear of COVID-19 infection, higher other-oriented emotional reactivity (a factor of MES), and higher health literacy.

Conclusion: We presented the WTP of the Japanese population for the transmission prevention function of COVID-19 treatments as an actual monetary value. Factors such as empathy, health literacy, and some attributes were significantly associated with WTP. These findings might help inform policymakers in developing health policies based on the universal health insurance system in Japan.