| Smoking status | Good knowledge | Poor knowledge | Total | Chi-square | p-value |
| Ever smoked | 54 (37.5%) | 90 (62.5%) | 144 | ||
| Never smoked | 542 (67.8%) | 258 (32.3%) | 800 | ||
| Total | 596 (64.4%) | 348 (36.9%) | 944 | 23.98 | <0.001 |