Smoking pattern of Vietnamese methadone maintenance treatment patients
| Characteristic | N (%) |
| Age at smoking initiation, mean years (SD) | 17.2 (3.5) |
| Duration of regular smoking, mean years (SD) | 14.1 (8.5) |
| Expense for smoking (1,000 VND per month), mean (SD) | 306.3 (289.4) |
| Fagerström test for nicotine dependence score, mean (SD) | 4.5 (2.4) |
| Nicotine dependence scale, n (%) | |
| Very low | 231 (26.1) |
| Low | 239 (27.0) |
| Moderate | 115 (12.9) |
| High | 184 (20.8) |
| Very high | 117 (13.2) |
| Number of cigarette per day, n (%) | |
| ≤10 | 409 (46.2) |
| 11–20 | 407 (45.9) |
| 21–30 | 49 (5.5) |
| >30 | 21 (2.4) |