Table 1 Variables definitions

Poverty

Fall in poverty = 1; Not fall in poverty = 0

Catastrophic health expenditure or not

The proportion of out-of-pocket expenses is over 10% of total household income per capita

(Yes = 1, No = 0)

Reimbursement expense ratio

0% = 0; 0 ~ 20% = 1; 20 ~ 40% = 2; 40 ~ 60% = 3; 60 ~ 80% = 4; 80 ~ 100% = 5

Interaction term

Disease shock and reimbursement expense ratio

Martial status

With spouse =1; without spouse = 0

Number of children

Continuous variable

Relationship with children

Very not harmonious = 1; not harmonious = 2; average = 3; harmonious = 4; very harmonious = 5

Financial support from children

0 yuan = 0; 0 ~ 1500 yuan = 1; 1500 ~ 3000 yuan = 2; 3000 ~ 4500 yuan = 3; 4500 ~ 6000 yuan = 4; more than 6000 yuan = 5

Frequency of face-to-face interaction with children

At least once within 1 week = 1; at least once within 1 month = 2; at lease once within 3 months = 3; at least once within semi-year = 4; at lease once within 1 year = 5

Frequency of interaction by telephone with children

At least once within 1 week = 1; at least once within 1 month = 2; at lease one within 3 months = 3; at least once within semi-year = 4; at least once within 1 year = 5

Social involvement

Continuous variable indicating how many kinds of social activities you participate

Economic involvement

Continuous variable indicating how many kinds of economic activities you participate

Gender

Male = 1, female = 0

Age

Continuous variable

Years for education

Continuous variable