Factors associated with high nicotine dependence
| Covariate | Percentage | Adjusted OR | 95% CI | P value |
| Residence | ||||
| Urban | 17.0 | 0.93 | 0.67 to 1.29 | 0.661 |
| Rural | 18.3 | Reference | ||
| Sex | ||||
| Male | 17.5 | 1.86 | 0.40 to 8.61 | 0.428 |
| Female | 20.0 | Reference | ||
| Age (years) | ||||
| 15–39 | 6.9 | 0.45 | 0.20 to 0.99 | 0.047 |
| 40–59 | 15.9 | 0.89 | 0.60 to 1.34 | 0.584 |
| ≥ 60 | 23.1 | Reference | ||
| Education level | ||||
| Primary or less | 24.4 | 3.07 | 1.15 to 8.18 | 0.025 |
| Secondary | 17.8 | 2.62 | 1.03 to 6.71 | 0.044 |
| High school | 8.6 | 1.26 | 0.45 to 3.55 | 0.655 |
| Undergraduate or above | 5.6 | Reference | ||
| Occupation | ||||
| Industrial worker | 25.7 | 2.46 | 1.45 to 4.15 | 0.001 |
| Government institution staff | 12.5 | 4.02 | 1.31 to 12.30 | 0.015 |
| Business/service worker | 12.6 | 1.68 | 0.95 to 2.99 | 0.075 |
| Unemployed | 28.9 | 3.08 | 1.56 to 6.05 | 0.001 |
| Retired | 16.3 | 1.54 | 0.71 to 3.32 | 0.271 |
| Others | 10.7 | Reference | ||
| Household yearly income (yuan) | ||||
| <50 000 | 23.9 | 1.77 | 0.89 to 3.51 | 0.104 |
| 50 000–200 000 | 14.0 | 1.37 | 0.70 to 2.67 | 0.360 |
| >200 000 | 10.4 | Reference | ||
| Age of starting daily smoking (years) | ||||
| ≤18 | 27.1 | 2.25 | 1.59 to 3.17 | <0.001 |
| >18 | 14.7 | Reference |