Table 1 Basic characteristics of participants
| Â | Number of children | |||
|---|---|---|---|---|
No Child | Children = 1 | Children = 2 | Children≥3 | |
N, % | 10,330, 2.01 | 183,628, 35.80 | 166,394, 32.44 | 152,539, 29.74 |
Socio-demographic characteristics | ||||
 Mean age, years (SD) | 49.55 (12.04) | 45.26 (7.37) | 50.64 (9.34) | 60.18 (9.47) |
 Female, % | 40.21 | 57.60 | 59.73 | 61.18 |
 Region is urban, % | 48.06 | 64.91 | 31.88 | 32.11 |
Socio-economic characteristics | ||||
 Highest education, % | ||||
  Primary school / below | 49.05 | 28.36 | 54.82 | 73.47 |
  High school / above | 50.95 | 71.64 | 45.18 | 26.53 |
 Household income, % | ||||
   < 10,000yuan | 69.23 | 44.5 | 56.53 | 72.71 |
   ≥ 10,000yuan | 30.77 | 55.5 | 43.47 | 27.29 |
 Occupation, % | ||||
  Agriculture and related | 39.96 | 24.17 | 52.46 | 51.26 |
  Factory workers | 16.57 | 28.57 | 9.14 | 1.97 |
  Clerk | 18.23 | 26.08 | 10.71 | 4.49 |
  Unemployed/Others | 25.24 | 21.17 | 27.68 | 42.28 |
 Marital status | ||||
  Married | 51.08 | 94.30 | 94.18 | 84.87 |
  Widowed/Divorced/Single | 48.92 | 5.70 | 5.82 | 15.13 |
Lifestyle factors | ||||
 Self-rated health, % | ||||
  Poor | 12.95 | 9.07 | 9.55 | 12.60 |
  Fair | 48.12 | 40.53 | 43.91 | 47.62 |
  Good | 22.53 | 28.59 | 30.13 | 25.76 |
  Excellent | 16.40 | 21.81 | 16.41 | 14.02 |
 BMI (kg/m2), % | ||||
   < 20 | 20.99 | 10.29 | 12.58 | 16.13 |
  20–25 | 54.61 | 56.17 | 55.52 | 53.27 |
   > 25 | 24.40 | 33.55 | 31.90 | 30.60 |
 Smoking, % | ||||
  Never | 48.14 | 61.11 | 63.17 | 62.49 |
  Ever smoke | 51.86 | 38.89 | 36.83 | 37.51 |
 Alcohol, % | ||||
  Never | 38.30 | 37.27 | 48.58 | 53.74 |
  Ever use | 61.70 | 62.73 | 51.42 | 46.26 |