Table 1. Baseline characteristics of the participants.
| Characteristics | Total | Precontemplation | Contemplation | Preparation | ||||
|---|---|---|---|---|---|---|---|---|
| Na | % (SE)b | Na | % (SE)b | Na | % (SE)b | Na | % (SE)b | |
| Sex | ||||||||
| Male | 41,544 | 92.6 (0.1) | 31,458 | 92.6(0.2) | 8,182 | 93.3(0.3) | 1,877 | 91.2(0.7) |
| Female | 3,834 | 7.4 (0.1) | 3,042 | 7.4(0.2) | 614 | 6.7(0.3) | 188 | 8.8(0.7) |
| Age (years) | ||||||||
| 19–29 | 5,100 | 17.4 (0.2) | 3,335 | 15.2(0.3) | 1432 | 22.8(0.6) | 333 | 23.1(1.1) |
| 30–39 | 9,146 | 23.8 (0.3) | 6,313 | 22.0(0.3) | 2297 | 28.2(0.6) | 536 | 29.0(1.1) |
| 40–49 | 11,627 | 26.8 (0.3) | 8,849 | 27.4(0.3) | 2317 | 26.1(0.5) | 461 | 21.6(1.0) |
| 50–59 | 9,847 | 20.0 (0.2) | 7,925 | 21.8(0.3) | 1571 | 15.3(0.4) | 351 | 15.9(1.0) |
| ≥60 | 9,658 | 12.1 (0.2) | 8,095 | 13.6(0.2) | 1179 | 7.5(0.3) | 384 | 10.5(0.6) |
| Marital status | ||||||||
| Single | 9,733 | 28.0 (0.3) | 7,003 | 26.5(0.3) | 2,234 | 32.1(0.6) | 496 | 31.4(1.2) |
| Married | 30,467 | 63.3 (0.3) | 23,222 | 64.0(0.3) | 5,851 | 61.6(0.6) | 1,394 | 61.7(1.3) |
| Widowed, divorced or other | 5,178 | 8.7 (0.2) | 4,292 | 9.5(0.2) | 711 | 6.3(0.3) | 175 | 6.9(0.6) |
| Education | ||||||||
| Elementary school or lower | 6,178 | 7.0 (0.1) | 5,409 | 8.3(0.2) | 600 | 3.7(0.2) | 169 | 3.7(0.3) |
| Middle school | 4,826 | 7.7 (0.1) | 4,021 | 8.7(0.2) | 652 | 5.1(0.3) | 153 | 5.1(0.5) |
| High school | 17,122 | 37.2 (0.3) | 13,348 | 39.3(0.3) | 3,144 | 33.6(0.6) | 630 | 28.8(1.1) |
| College/university or higher | 17,252 | 48.1 (0.3) | 11,739 | 44.1(0.3) | 4,400 | 57.6(0.6) | 1,113 | 62.4(1.2) |
| Income (million KRW) | ||||||||
| <1 | 7,604 | 10.3 (0.2) | 6,312 | 11.3(0.2) | 1,012 | 7.4(0.3) | 280 | 8.7(0.6) |
| 1–2 | 7,939 | 14.8 (0.2) | 6,278 | 15.3(0.2) | 1,353 | 13.8(0.4) | 308 | 12.7(0.9) |
| 2–3 | 9,974 | 22.6 (0.3) | 7,478 | 22.4(0.3) | 2,046 | 23.1(0.5) | 450 | 22.1(1.0) |
| 3–4 | 8,081 | 20.0 (0.3) | 5,957 | 19.7(0.3) | 1,754 | 21.3(0.5) | 370 | 18.6(1.0) |
| ≥4 | 11,780 | 32.4 (0.3) | 8,492 | 31.4(0.3) | 2,631 | 34.4(0.6) | 657 | 37.9(1.3) |
| Alcohol consumption (No. of times/week) | ||||||||
| None | 6,286 | 9.7 (0.2) | 5,160 | 10.6(0.2) | 901 | 7.5(0.3) | 225 | 6.9(0.5) |
| ≤1 | 18,140 | 44.3 (0.3) | 13,039 | 42.2(0.3) | 4,045 | 48.9(0.6) | 1,056 | 53.9(1.3) |
| ≥2 | 20,952 | 46.0 (0.3) | 16,318 | 47.2(0.3) | 3,850 | 43.5(0.6) | 784 | 39.2(1.3) |
| Self-reported stressc | ||||||||
| Low | 30,520 | 64.6 (0.3) | 23,389 | 65.1(0.3) | 5,771 | 63.2(0.6) | 1,360 | 62.6(1.2) |
| High | 14,858 | 35.4 (0.3) | 11,128 | 34.9(0.3) | 3,025 | 36.8(0.6) | 705 | 37.4(1.2) |
| Residence in districts with smoke-free regulationd | ||||||||
| No | 18,319 | 23.3 (0.2) | 14,410 | 24.3(0.2) | 3,177 | 21.4(0.5) | 732 | 18.6(0.8) |
| Yes | 27,059 | 76.7 (0.2) | 20,107 | 75.7(0.2) | 5,619 | 78.6(0.5) | 1,333 | 81.4(0.8) |
| Age of smoking commencement (year) | ||||||||
| <19 | 14,896 | 35.2 (0.3) | 11,264 | 35.2(0.3) | 2,951 | 35.4(0.6) | 681 | 35.2(1.2) |
| ≥19 | 30,482 | 64.8 (0.3) | 23,253 | 64.8(0.3) | 5,845 | 64.6(0.6) | 1,384 | 64.8(1.2) |
| Cigarettes smoked per day | ||||||||
| <10 | 7,890 | 17.8 (0.2) | 5,254 | 14.9(0.2) | 1,757 | 20.9(0.5) | 879 | 44.2(1.3) |
| 10–20 | 17,038 | 40.7 (0.3) | 12,558 | 39.6(0.3) | 3,765 | 45.5(0.6) | 715 | 35.4(1.2) |
| 20–40 | 19,060 | 39.1 (0.3) | 15,502 | 42.7(0.3) | 3,110 | 32.4(0.6) | 448 | 19.2(0.9) |
| ≥40 | 1,390 | 2.3 (0.1) | 1,203 | 2.8(0.1) | 164 | 1.2(0.1) | 23 | 1.2(0.3) |
| Family smoking statuse | ||||||||
| None | 41,767 | 91.1 (0.2) | 31,784 | 91.2(0.2) | 8,082 | 90.6(0.4) | 1,901 | 91.3(0.8) |
| Any | 3,611 | 8.9 (0.2) | 2,733 | 8.8(0.2) | 714 | 9.4(0.4) | 164 | 8.7(0.8) |
| Quit attempts | - | - | - | - | - | - | ||
| None | 15,702 | 32.8 (0.3) | ||||||
| Before 1 year ago | 18,884 | 40.3 (0.3) | ||||||
| Within the past 1 year | 10,792 | 26.8 (0.3) | ||||||
| Intention to quit | - | - | - | - | - | - | ||
| None | 13,058 | 25.5 (0.3) | ||||||
| Someday | 21,459 | 46.8 (0.3) | ||||||
| Within the next 6 months | 7,382 | 19.2 (0.2) | ||||||
| Within the next 30 days | 3,479 | 8.5 (0.2) | ||||||
| Stage of change | - | - | - | - | - | - | ||
| Precontemplation | 34,517 | 72.3 (0.3) | ||||||
| Contemplation | 8,796 | 22.5 (0.3) | ||||||
| Preparation | 2,065 | 5.2 (0.1) | ||||||
aData were not weighted (total N = 45,378).
bData were weighted to yield nationally representative estimates.
cSelf-reported stress was categorized as ‘low’ for participants who felt seldom or a little stressed, and ‘high’ in participants who experienced too much stress in daily.
dDistricts with smoke-free regulation are defined as municipalities that introduced comprehensive smoke-free regulation at least two years before the survey.
eQuestionnaire on whether someone else in their household routinely smokes in the home indoor.
SE, standard error; KRW, Korean won.