Social participation
First, we asked whether the respondents engaged in any community-based social participation activities. The respondents answered “yes” or “no.” For people who participated in any activity, we further asked about the type of activity such as “neighborhood associations,” “senior clubs,” “volunteer groups,” “hobby groups, sports groups, or learning groups.”Second, we asked about the respondent’s attitudes and intentions toward social participation as the outcome variables because previous studies regarding the effects of message framing on health-related outcomes focused on three domains (attitudes, intentions, and behaviors) [The intention for social participation includes an interest in and readiness for social participation activities. Interest in social participation activities was assessed using the item: “How interested are you in social participation activity now?” with answers scored using a six-point Likert scale (“1 = I am not interested in it at all,” “2 = I am not interested in it,” “3 = I am not much interested in it,” “4 = I am somewhat interested in it,” “5 = I am interested in it,” or “6 = I am very interested in”). Readiness for social participation activities was assessed after preparing items for those with and without participation in any social participation activity as “How would you like to change the frequency and variation of social participation activities you are currently engaged in in the future?” (scored using a three-point Likert scale: “1 = I would like to decrease the frequency and variation,” “2 = I would like to keep the current situation unchanged,” or “3 = I would like to increase the frequency and variation”) and “How much would you like to initiate social participation activities?” (scored using a three-point Likert scale: “1 = I will not begin activities,” “2 = I would eventually like to begin activities,” or “3 = I would like to begin activities in the near future”), respectively.