Table 4 The assignments of independent variables

Age of the child (years)

1=<3; 2 = 4 ∼ 6; 3>6

Course of the disease (years)

1=<1; 2 = 2 ∼ 5; 3>5

Self-care ability

1 = takes care of oneself; 2 = assisted; 3 = relies entirely on others

Parents’ age (years)

1=<35; 2 = 36 ∼ 40; 3>40

Gender

1 = male; 2 = female

Medical expense

1 = free; 2 = national health insurance; 3 = at one’s own expense

Marital status

1 = married; 2 = single

Working condition

1 = working; 2 = unemployed

Family income annually (CNY)

1 = CN<≤50,000; 2 = CNY 50,000-100,000; 3 = CNY 100,000-150,000; 4 = CNY>150,000

Settlement

1 = rural area; 2 = city; 3 = suburb

Educational background

1 = primary school; 2 = middle school; 3 = university; 4 = Master’s degree or above

Number of children

1 = 1; 2 = 2; 3=>3

Health condition

1 = poor; 2 = normal; 3 = in good shape