Table 1 Description of variables

Household expenditure (CNT)

Total consumption expenditure of a household.

OOP medical expenditure (CNY)

Total out-of-pocket medical expenditure of a household.

Food expenditure (CNY)

Total food consumption expenditure of a household.

Household income (CNY)

The annual household income per capita.

Household size

The number of household members.

Inpatient

At least one household member received inpatient services in last year; Yes = 1; No = 0^a.

Household members aged<=5

At least one household member below 5 years old; Yes = 1; No = 0^a.

Household members aged> = 60

At least one household member over 60 years old; Yes = 1; No = 0^a.

Geographic location

East = 1^a; Central = 2; West = 3.

Gender of household head

Female = 0^a; Male = 1.

Education of household head

Illiterate = 1^a; Primary school = 2; Middle school = 3; High school and above = 4.

Marriage of household head

Married = 1; Unmarried = 0^a.

Self-assessed health status of household head

Unhealthy = 0^a; Healthy = 1.

Basic medical insurance

No medical insurance = 1^a; UEBMI = 2; URBMI = 3; NRCMS = 4; Two kind of medical insurance = 5

SMI

The household head is covered by SMI; Yes = 1; No = 0^a.