Category	Code of the Variable	Variable	Question	Responses
Social media use during the last 12 months	Soc_MedVisited	Visiting social media	In the last 12 months, how often did you visit a social media site?	“Daily,” “sometimes a month,” “less than once a month.”
	SocMed_SharedPers	Using SM to share personal health information	In the last 12 months, how often did you share personal health information on social media?	“Daily,” “sometimes a month,” “less than once a month.”
	SocMed_SharedGen	Using SM to share general health information	In the last 12 months, how often did you share general health-related information on social media (for example, a news article)?	“Daily,” “sometimes a month,” “less than once a month.”
	SocMed_Interacted	Using SM to interact with people with similar health issues	In the last 12 months, how often did you interact with people with similar health or medical issues on social media or online forums?	“Daily,” “sometimes a month,” “less than once a month.”
	SocMed_WatchedVid	Using SM to watch health-related videos	In the last 12 months, how often did you watch a health-related video on a social media site (for example, YouTube)?	“Daily,” “sometimes a month,” “less than once a month.”
Perceptions of social media use for health-related purposes	SocMed_MakeDecisions	Using SM information to make decisions about their health	How much do you agree or disagree—I can use information from social media to make decisions about my health.	“Strongly agree,” “agree,” “somewhat disagree,” and “strongly disagree.”
	SocMed_DiscussHCP	using SM information in discussions with their healthcare providers	How much do you agree or disagree—I can use information from social media in discussions with my healthcare provider.	“Strongly agree,” “agree,” “somewhat disagree,” and “strongly disagree.”
	SocMed_TrueFalse	Finding it hard to tell if SM information is true or false	How much do you agree or disagree—I find it hard to tell whether health information on social media is true or false.	“Strongly agree,” “agree,” “somewhat disagree,” and “strongly disagree.”
	SocMed_SameViews	People on SM have the same views about health as them	How much do you agree or disagree? Most people in my social media networks have the same views about health as I do.	“Strongly agree,” “agree,” “somewhat disagree,” and “strongly disagree.”
	MisleadingHealthInformation	Health-related information on SM being misleading.	How much health information do you see on social media that you think is false or misleading?	“Strongly agree,” “agree,” “somewhat disagree,” and “strongly disagree.”
Personal factors	Age	Age categories	What is your age?	“18–34”,“35–49”,“50–64”,“65 or more”
	Race	Race categories	What is your race?	“White”, “Black”, “Hispanic”, “Other”
	Education	Education categories	What is the highest degree you obtained?	“Some high school or less,” “High school graduate,” “Some college,” “College graduate or more”
	Income	Income categories	What is your yearly income?	“Less than 20K”, “20k to 35k”, “35k to 50k”, “50k to 75k”, “75k or more”
	Gender	Gender categories	What is your gender?	“Female”, “Male”
	general health	Health Perception	In general, how would you describe your health?	“Bad”, “good”, “fair”
	SelfEfficacy	One’s ability to take care of their health	Overall, how confident are you about taking good care of your health?	“Bad”, “good”, “fair”
Environmental factors	FeelIsolated	Feeling isolated	I feel isolated from others	“Yes,” “No,” “Somehow”
	FeelLeftOut	Feeling left out	I feel left out	“Yes,” “No,” “Somehow”
	FeeLPeopleBarelyLKnow	Feel that people barely know them	I feel that people barely know me	“Yes,” “No,” “Somehow”
	FeelPeopleNotWithMe	Feel that people are around but not with them	I feel that people are around me but not with me	“Yes,” “No,” “Somehow”
	PROMIS Social Isolation	Feeling isolated from people	The score of the previous four questions	“Yes,” “No,” “Somehow”
	LifeHasMeaning	Feeling that life has a meaning	My life has meaning	“Yes,” “No,” “Somehow”
	LifeHasPurpose	Feeling that life has a purpose	My life has a purpose	“Yes,” “No,” “Somehow”
	ClearSenseDirection	Having a clear sense of direction in life	I have a clear sense of direction in my life	“Yes,” “No,” “Somehow”
	PROMIS Meaning and Purpose in Life	Having a meaning and purpose to life	The score of the previous questions	“Yes,” “No,” “Somehow”