Table 1.
Basic characteristics of survey subjects (N=12278)
| Weighted | Unweighted | ||
|---|---|---|---|
| Mean (95% CI) | Number | Mean (95% CI) | |
| Age (years) | 14.28 (14.23–14.31) | 670050 | 14.62 (14.58–14.66) |
| % (95% CI) | Number | n (%) | |
| Type of school | |||
| Junior high school | 61.99 (61.13–62.85) | 415377 | 6462 (52.63) |
| Senior high school | 23.67 (22.88–24.48) | 158593 | 2475 (20.16) |
| Vocational high school | 14.34 (13.86–14.83) | 96080 | 3341 (27.21) |
| District | |||
| Urban | 33.36 (33.13–33.60) | 223534 | 4042 (32.92) |
| Suburban | 66.64 (66.40–66.87) | 446516 | 8236 (67.08) |
| Gender | |||
| Male | 51.6 (50.69–52.52) | 345778 | 6419 (52.28) |
| Female | 48.4 (47.48–49.31) | 324272 | 5859 (47.72) |
| Residence | |||
| Local | 72.21 (71.39–73.02) | 483864 | 8755 (71.31) |
| Non-local | 27.79 (26.98–28.61) | 186186 | 3523 (28.69) |
| Boarding in school | |||
| Yes | 13.55 (13.00–14.12) | 90791 | 2302 (18.75) |
| No | 86.45 (85.88–87.00) | 579260 | 9976 (81.25) |
| Monthly allowance (RMB) | |||
| <200 | 61.23 (60.35–62.11) | 173882 | 7011 (57.10) |
| 200–600 | 25.95 (25.17–26.75) | 85865 | 3401 (27.70) |
| >600 | 12.81 (12.24–13.41) | 670050 | 1866 (15.20) |
| GPA | |||
| Top 25% | 32.96 (32.11–33.83) | 220860 | 3924 (31.96) |
| Average | 46.28 (45.38–47.20) | 310129 | 5712 (46.52) |
| Bottom 25% | 20.75 (20.03–21.5) | 139061 | 2642 (21.52) |
| Parents’ smoking | |||
| None | 36.56 (35.68–37.44) | 244962 | 4377 (35.65) |
| One | 59.25 (58.35–60.14) | 396985 | 7364 (59.98) |
| Both | 4.19 (3.85–4.57) | 28103 | 537 (4.37) |
| Friends’ smoking | |||
| None | 82.79 (82.13–83.43) | 554740 | 9693 (78.95) |
| Some | 15.16 (14.55–15.79) | 101550 | 2274 (18.52) |
| Most or all | 2.05 (1.83–2.31) | 13760 | 311 (2.53) |
| Smoking status | |||
| Never | 92.12 (91.64–92.57) | 617244 | 11091 (90.33) |
| Ever | 5.36 (4.98–5.76) | 35893 | 780 (6.35) |
| Current | 2.52 (2.28–2.80) | 16913 | 407 (3.31) |
| Smoking susceptibility | |||
| No | 92.33 (91.86–92.78) | 618651 | 11140 (90.73) |
| Yes | 7.67 (7.22–8.14) | 51399 | 1138 (9.27) |
| E-cigarette use | |||
| No | 92.33 (91.86–92.78) | 618651 | 11524 (93.86) |
| Yes | 7.67 (7.22–8.14) | 51399 | 754 (6.14) |
CI: confidence interval. GPA: grade point average. RMB: 100 Chinese Renminbi about US$15.