Table 1.
Baseline characteristics of the participating youths
| Variables | High school students |
Undergraduate students |
Graduate students |
All |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| male (n = 678) | female (n = 2,146) | total (n = 2,824) | male (n = 2,106) | female (n = 4,918) | total (n = 7,024) | male (n = 68) | female (n = 166) | total (n = 234) | grand total (n = 10,082) | |
| Age, years | 17.5±1.2 | 17.5±1.2 | 17.5±1.2 | 20.6±2.0 | 20.6±1.6 | 20.6±1.8 | 24.3±4.1 | 24.7±3.2 | 24.6±3.5 | 19.8±2.3 |
| Ethnic | ||||||||||
| Han | 96.9 | 96.7 | 96.7 | 94.2 | 95.1 | 94.8 | 92.6 | 92.2 | 92.3 | 95.3 |
| Minority | 3.1 | 3.3 | 3.3 | 5.8 | 4.9 | 5.2 | 7.4 | 7.8 | 7.7 | 4.7 |
| Urbanicity | ||||||||||
| Urban | 31.9 | 22.1 | 24.4 | 40.2 | 41.3 | 41.0 | 57.4 | 63.3 | 61.5 | 36.8 |
| Nonurban | 68.1 | 77.9 | 75.6 | 59.8 | 58.7 | 59.0 | 42.6 | 36.7 | 38.5 | 63.2 |
| Region | ||||||||||
| Northeast | - | - | - | 0.3 | 0.2 | 0.3 | 2.9 | 4.2 | 3.8 | 0.3 |
| East | 0.6 | 0.7 | 0.7 | 10.1 | 12.2 | 11.5 | 25.0 | 28.3 | 27.4 | 8.9 |
| West | 99.4 | 99.3 | 99.3 | 85.5 | 84.1 | 84.5 | 61.8 | 50 | 53.4 | 87.9 |
| Central | - | - | - | 4.1 | 3.5 | 3.7 | 10.3 | 17.5 | 15.4 | 2.9 |
| Household income, RMB/year | ||||||||||
| <20,000 | 48.8 | 63.6 | 60.0 | 44.8 | 46.7 | 46.1 | 17.6 | 15.7 | 16.3 | 49.3 |
| ≥20,000–60,000 | 28.3 | 25.0 | 25.8 | 26.4 | 28.1 | 27.6 | 14.8 | 24.7 | 21.8 | 27.0 |
| ≥60,000–10,0000 | 15.2 | 7.8 | 9.6 | 14.8 | 13.4 | 13.8 | 22.1 | 22.9 | 22.6 | 12.8 |
| ≥ 100,000 | 7.7 | 3.6 | 4.6 | 14.0 | 11.8 | 12.5 | 45.5 | 36.7 | 39.3 | 10.9 |
| Major | ||||||||||
| Medical science | 59.0 | 98.4 | 89.0 | 72.4 | 76.0 | 14.9 | 47.2 | 52.4 | 49.1 | 36.4 |
| Science/engineering | 39.4 | 1.0 | 10.2 | 57.9 | 22.6 | 31.4 | 44.7 | 20.5 | 27.4 | 25.4 |
| Social science | 1.6 | 0.6 | 0.8 | 35.7 | 61.4 | 53.7 | 74.7 | 27.1 | 23.5 | 38.2 |
Values are given as a percentage or mean ± SD. SD, standard deviation. Values under a given variable were shown in bold, if the difference a cross educational levels (High school students, undergraduate students, and graduate students) within the overall population (total) or within a given sex (male and female) was significant (p < 0.05); shown in italic, if the difference between sexes within a given educational level was significant (p < 0.05).