Table 1 Study measures

Demographic characteristics

· Age (reclassified as 19–29, 30–49, 50–69, ≥ 70 years)

· Gender (male, female)

· Education (under elementary school, middle/high school, associate/bachelor’s degree, master’s or higher degree)

· Monthly household income (reclassified as less than 100, 101–300, 301–500, ≥ 501; ten thousand won unit)

· Type of household (single-person household, household with two or more members)

· Working status (yes/no)

· Influenza vaccination (yes/no)

· Daily life stress (seldom felt, felt a little, felt much, extremely felt)

Li et al. [31]

Beaudoin et al. [32]

Gunderson et al. [33]

Tang et al. [34]

Peterson et al. [35]

COVID-19 preventive behaviors

 Wearing a mask

· Did you cover your mouth and nose with your sleeve when sneezing or coughing?

· Did you wear a mask in indoor facilities used by unspecified people?

· Did you wear a mask if it is difficult to keep a distance of more than two meters between people outdoors?

Li et al. [31]

Graupensperger et al

[36]

Monnig et al. [37]

 Social distancing

· Did you maintain a two-meter distance between people for your health?

· Did you refrain from going outside/meetings/events?

 Hand washing

· How often did you wash your hands after returning from outside?

· Did you thoroughly wash your hands under running water for at least 30 s?

· How often do you use soap or hand sanitizer when washing your hands?

Perceived threat

 Perceived severity

· I am concerned that I will die if I become infected

with COVID-19

· I am concerned that the COVID-19 epidemic will

cause economic damage to my family and myself

including losing my job or difficulty in finding a job

Rayani et al. [38]

Beaudoin et al. [32]

Fujii et al. [39]

 Perceived susceptibility

· I am concerned that I will be infected with COVID-19

· I am concerned that my family and other vulnerable people (older people, infants, and patients) will become infected with COVID-19

Perceived social factors

 Perceived stigma

· I am concerned that I will be criticized or harmed by

those around me if I am infected with COVID-19

Hong et al. [27]

 Perceived institutional response ability

· Do you think the COVID-19 response ability of each of the following institutions is appropriate?

- government including the Ministry of Health and Welfare

and the Korea Centers for Disease Control and Prevention

- mass media such as broadcasting and newspapers

- local medical institutions

- neighbors and co-workers

Chen et al. [25]

Rieger et al. [24]

Liu & Mesch [40]