Table 1. Summary of variables.

Variables	Question	Category
Outcome variable
Suicidal ideation	Have you ever thought of wanting to die in the past year?	Never or ever
Sociodemographic factors
Age group	What is your age?	19–49, 50–64, 65–79, or ≥80 years
Residential region	Is your place of residence urban or rural?	Urban or rural
Marital status	Have you ever been married (including a common law marriage)? What is your current marital status?	Never married, married, divorced/separated, or widowed
Educational level	Where did you go to school? Did you graduate from school?	Non-formal education, primary school, middle or high school, or college or higher
Monthly household income	What was your average monthly household income in the past year, including wages, real estate income, pensions, interest, government subsidies, and allowances for relatives or children?	≤1, 1.01–2, 2.01–4, or ≥4.01 million KRW
Employment status	What occupation are you currently engaged in?	Employed, unemployed, or housewife/student
National Basic Livelihood Security status	Does your household currently receive National Basic Livelihood Security?	Recipient or non-recipient
Socio-family relationships
Family contact	How often do you see or contact your closest relative (family member)?	<1 or ≥1 time per month
Neighbor contact	How often do you see or contact your closest neighbors?	<1 or ≥1 time per month
Friend contact	How often do you see or contact your most frequently contacted friends?	<1 or ≥1 time per month
Religious activity	Do you regularly engage in religious activities at least once a month?	<1 or ≥1 time per month
Friendship activity	Do you regularly engage in friendship activities at least once a month?	<1 or ≥1 time per month
Leisure activity	Do you regularly engage in leisure activities at least once a month?	<1 or ≥1 time per month
Charitable activity	Do you regularly engage in charitable activities at least once a month?	<1 or ≥1 time per month
Health behaviors and health status
Smoking status	Have you smoked more than 100 cigarettes during your life? Do you smoke now?	Never smoker, former smoker, or current smoker
Frequency of alcohol use	Have you been drinking for the last year? How often do you drink alcohol?	None, ≤1, 2–3, or ≥4 times per week
Moderate physical activity		≤2 or ≥3 times per week
Walking activity	How many days did you walk for at least 10 minutes at a time in the last week?	≤2 or ≥3 times per week
Sleep duration	How many hours a day do you usually sleep?	≤6, 7–8, or ≥9 h per day
Perceived usual stress level	How often do you feel stressed in your usual life?	High (very often or often) or low (rarely or almost never)
Experience of depressive mood	Have you ever felt sad or desperate for more than 2 weeks in a row during the past year?	No or yes
Self-rated health	What do you think about your health?	Good, fair, or poor
Diagnosis of hypertension	Have you been diagnosed with hypertension?	Never or ever
Diagnosis of diabetes	Have you been diagnosed with diabetes?	Never or ever
Diagnosis of depression	Have you been diagnosed with depression?	Never or ever