Table 2 Descriptive statistics of variables (N = 7782)

QWB

Calculated according to the QWB scale and the AHP method

SHS

Self-reported subjective health status, “very poor” = 1, “relatively poor” = 2, “fair” = 3, “relatively good” = 4, “very good” = 5

ISS

ISS = SE×0.2 + PSS×0.3 + ES×0.5

SE

The number of friends respondents could see or communicate with at least once a month, “none” = 0, “only 1” = 1, “only 2” = 2, “3–4” = 3, “5–8” = 4, “9 and more” = 5

PSS

The number of friends with whom respondents can communicate or share private matters with confidence, “none” = 0, “only 1” = 1, “only 2” = 2, “3–4” = 3, “5–8” = 4, “9 and more” = 5

ES

The number of friends who can provide some help when the respondent is in need, “none” = 0, “only 1” = 1, “only 2” = 2, “3–4” = 3, “5–8” = 4, “9 and more” = 5

GEN

“Female” = 0, “Male” = 1

AGE

Year surveyed (2018) minus respondents’ birth year

EDU

“Not attending school” = 1, “primary school” = 2, “middle school” = 3, “high school/technical secondary school” = 4, “junior college” = 5, “university and above” = 6

SPOUSE

“No spouse” = 0, “have a spouse” = 1

HUKOU

“Agricultural household registration” = 0, “Non-agricultural household registration” = 1

PENS

“None” = 0, “Having participated in Basic endowment insurance for urban employees / endowment insurance for government agencies and institutions / basic endowment insurance for urban and rural residents” = 1

PINCO

Total personal income in the past year

ACT

The frequency of activity / work in the past week, “never” = 1, “sometimes” = 2, “often” = 3

NCHIL

The number of living children

HINCO

The average monthly household income in the past year