Waves 1–3 retention numbers and rates for adult male non-smokers
| City | Wave 1 sample | Wave 2 recontacts | Wave 3 recontacts |
|---|---|---|---|
| Beijing | 99 | 97 (98.0%) | 93 (93.9%) |
| Shenyang | 64 | 56 (87.5%) | 45 (70.3%) |
| Shanghai | 91 | 82 (90.1%) | 78 (85.7%) |
| Changsha | 86 | 64 (74.4%) | 47 (54.7%) |
| Guangzhou | 92 | 51 (55.4%) | 41 (44.6%) |
| Yinchuan | 83 | 63 (75.9%) | 46 (55.4%) |
| Total | 515 | 413 (80.2%) | 350 (68.0%) |