Characteristics of subjects (five groups)
| Affected and quit | Affected and reduced smoking amount | Affected and changed smoking behaviour in other waysa) | Unaffected but quit smoking | Unaffected and continued smoking | P value for χ2 | ||||||
| N (%, weighted) | N (%, weighted) | N (%, weighted) | N (%, weighted) | N (%, weighted) | |||||||
| 15 499 (35.85) | 26 106 (64.15) | ||||||||||
| 1772 | (3.96) | 9714 | (22.48) | 4013 | (9.41) | 2401 | (5.72) | 23 705 | (58.44) | ||
| Monthly household income (unit: million KRW) | |||||||||||
| <1 (US$845) | 374 | (5.71) | 2017 | (33.94) | 691 | (11.35) | 428 | (6.30) | 2607 | (42.70) | <0.001 |
| (1–1.99) | 320 | (4.27) | 1837 | (26.41) | 792 | (12.03) | 357 | (4.90) | 3604 | (52.39) | |
| (2–2.99) | 337 | (3.55) | 2096 | (23.62) | 908 | (9.75) | 505 | (5.41) | 5231 | (57.67) | |
| (3–3.99) | 301 | (3.67) | 1630 | (20.90) | 673 | (9.00) | 431 | (5.61) | 4785 | (60.82) | |
| ≥4 (US$3380) | 440 | (3.85) | 2134 | (18.45) | 949 | (8.00) | 680 | (6.14) | 7478 | (63.56) | |
| Age (years) | |||||||||||
| 19–29 | 155 | (3.54) | 1083 | (24.48) | 432 | (9.53) | 247 | (5.66) | 2633 | (56.79) | <0.001 |
| 30–39 | 277 | (3.35) | 1670 | (19.98) | 693 | (8.66) | 445 | (5.91) | 5096 | (62.10) | |
| 40–49 | 383 | (3.84) | 2165 | (19.99) | 996 | (9.04) | 455 | (4.78) | 6506 | (62.35) | |
| 50–59 | 362 | (3.96) | 2066 | (22.17) | 1036 | (10.43) | 462 | (5.44) | 5277 | (57.99) | |
| 60–69 | 332 | (5.65) | 1474 | (27.97) | 575 | (10.46) | 446 | (7.72) | 2680 | (48.20) | |
| ≥70 | 263 | (6.76) | 1256 | (35.34) | 281 | (8.54) | 346 | (8.41) | 1513 | (40.95) | |
| Education level | |||||||||||
| ≤Middle school | 529 | (5.04) | 2723 | (29.74) | 993 | (11.47) | 646 | (6.17) | 4232 | (47.57) | <0.001 |
| Mid. sch. to Univ. | 877 | (3.63) | 5363 | (23.25) | 2299 | (9.90) | 1174 | (5.16) | 13 663 | (58.09) | |
| ≥University | 366 | (4.19) | 1628 | (17.65) | 721 | (7.47) | 581 | (6.71) | 5810 | (63.98) | |
| Marital status | |||||||||||
| Single | 447 | (3.35) | 3130 | (23.86) | 1356 | (10.20) | 557 | (4.65) | 7310 | (57.94) | <0.001 |
| Married | 1325 | (4.29) | 6584 | (21.74) | 2657 | (8.99) | 1844 | (6.28) | 16 395 | (58.70) | |
| Number of household members | |||||||||||
| One | 180 | (3.44) | 1105 | (23.10) | 540 | (11.13) | 223 | (4.84) | 2637 | (57.48) | <0.001 |
| Two | 663 | (4.76) | 3214 | (23.74) | 1228 | (10.28) | 884 | (6.55) | 6649 | (54.68) | |
| Three or more | 929 | (3.77) | 5395 | (21.95) | 2245 | (8.85) | 1294 | (5.56) | 14 419 | (59.87) | |
| Type of community | |||||||||||
| City (urban) | 1006 | (4.00) | 5453 | (22.15) | 2236 | (9.24) | 1378 | (5.85) | 14 005 | (58.76) | 0.003 |
| Town (rural) | 766 | (3.81) | 4261 | (23.83) | 1777 | (10.13) | 1023 | (5.16) | 9700 | (57.07) | |
| High-risk alcohol drinking | |||||||||||
| Yes | 498 | (3.45) | 2646 | (19.44) | 1418 | (10.54) | 610 | (4.79) | 8182 | (61.78) | <0.001 |
| No | 1274 | (4.22) | 7068 | (24.00) | 2595 | (8.84) | 1791 | (6.18) | 15 523 | (56.76) | |
| Physical activity | |||||||||||
| No | 1282 | (3.92) | 7185 | (22.59) | 2892 | (9.34) | 1757 | (5.68) | 17 401 | (58.47) | 0.854 |
| Yes | 490 | (4.08) | 2529 | (22.14) | 1121 | (9.62) | 644 | (5.81) | 6304 | (58.35) | |
| Self-reported stress level | |||||||||||
| High | 440 | (3.20) | 3017 | (21.42) | 1440 | (10.69) | 623 | (4.87) | 7598 | (59.82) | <0.001 |
| Low | 1332 | (4.37) | 6697 | (23.04) | 2573 | (8.73) | 1778 | (6.17) | 16 107 | (57.70) | |
| Experience of depression | |||||||||||
| Yes | 85 | (3.27) | 671 | (26.34) | 308 | (13.36) | 107 | (4.64) | 1181 | (52.40) | <0.001 |
| No | 1687 | (4.01) | 9043 | (22.24) | 3705 | (9.17) | 2294 | (5.78) | 22 524 | (58.81) | |
| Number of chronic diseases† | |||||||||||
| Two or more | 282 | (4.44) | 1523 | (24.03) | 607 | (9.83) | 461 | (7.62) | 2938 | (54.08) | <0.001 |
| One | 517 | (4.24) | 2535 | (22.90) | 1037 | (9.66) | 664 | (5.78) | 6072 | (57.42) | |
| Zero | 973 | (3.75) | 5656 | (21.98) | 2369 | (9.22) | 1276 | (5.30) | 14 695 | (59.75) | |
*Other changes including ‘switched to cheaper brands’, ‘switched to e-cigarettes’, ‘switched to non-cigarette tobacco products’ and ‘other’.
†Doctor-diagnosed high blood pressure, diabetes, hyponatraemia, arthritis, allergens, asthma or atopic dermatitis.