Table 1.
Demographic and socioeconomic characteristics of the subjects.
| Characteristic | N (%) or mean ± SD |
|---|---|
| Birth weight | 3294.9 ± 484.8 g |
| Age groups | |
| 0–11 months | 27.1% (8746/32,276) |
| 12–23 months | 16.2% (5234/32,276) |
| 24–35 months | 14.2% (4567/32,276) |
| 36–47 months | 14.8% (4787/32,276) |
| 48–59 months | 14.4% (4652/32,276) |
| 60–71 months | 13.3% (4290/32,276) |
| Gender | |
| Girl | 48.6% (15,680/32,276) |
| Boy | 51.4% (16,596/32,276) |
| Residential area | |
| Urban-metropolis | 22.6% (7299/32,276) |
| Urban-middle or small cities | 28.6% (9220/32,276) |
| Rural-non-poor areas | 32.7% (10,565/32,276) |
| Rural-poor areas | 16.1% (5192/32,276) |
| Ethnicitya | |
| Han | 86.9% (28,037/32,267) |
| Minority | 13.1% (4230/32,267) |
| Maternal age groupsb | |
| < 20 years | 1.2% (355/30,421) |
| 20–25 years | 25.1% (7627/30,421) |
| 26–30 years | 37.2% (11,321/30,421) |
| 31–35 years | 24.1% (7333/30,421) |
| > 35 years | 12.4% (3785/30,421) |
| Maternal educationc | |
| Primary or below | 12.6% (3841/30,599) |
| Junior high school | 47.2% (14,450/30,599) |
| High school | 18.2% (5569/30,599) |
| Associate's degree | 11.1% (3392/30,599) |
| Bachelor's degree or above | 10.9% (3347/30,599) |
| Annual household income (per capital CNY)d | |
| < 10,000 | 34.8% (11,242/32,261) |
| 10,000–19,999 | 27.6% (8888/32,261) |
| ≥ 20,000 | 27.5% (8880/32,261) |
| Refuse to response | 10.1% (3251/32,261) |
aThe ethnic information for 9 subjects was missing.
bInformation on maternal age was missing in 1855 subjects.
cInformation on the maternal educational level was missing in 1677 subjects.
dInformation on the annual household income was missing in 15 subjects.