Graduate School of Public Health, Seoul National University, Seoul, Korea.
Copyright © 2012 The Korean Society for Preventive Medicine
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The authors have no conflicts of interest with the material presented in this paper.
This article is available at http://jpmph.org/.
Subject characteristics |
All pairs (Sibling + twins)1 |
Monozygotic twins |
||
---|---|---|---|---|
Male | Female | Male | Female | |
No. of participants | 732 (38.85) | 1152 (61.15) | 332 (37.39) | 556 (62.61) |
Age (y) | 39.72 (8.21) | 39.04 (7.83) | 39.15 (7.50) | 37.78 (7.05) |
Education level | ||||
Middle school or lower | 96 (13.11) | 155 (13.45) | 46 (13.86) | 53 (9.53) |
High school | 338 (46.17) | 583 (50.61) | 146 (43.98) | 290 (52.16) |
College or higher | 298 (40.71) | 414 (35.94) | 140 (42.17) | 213 (38.31) |
Equivalized household income | ||||
≤252 | 177 (24.18) | 272 (23.61) | 55 (16.57) | 85 (15.29) |
25 - 753 | 434 (59.29) | 665 (57.73) | 210 (63.25) | 324 (58.27) |
>754 | 120 (16.39) | 215 (18.66) | 67 (20.18) | 147 (26.44) |
Occupation | ||||
Manual | 278 (37.98) | 200 (17.36) | 118 (35.54) | 98 (17.63) |
Non-manual | 400 (54.64) | 414 (35.94) | 193 (58.13) | 218 (39.21) |
Others5 | 54 (7.38) | 538 (46.70) | 21 (6.33) | 240 (43.17) |
Smoking status | ||||
Non-smoker | 172 (23.50) | 1025 (88.98) | 84 (25.38) | 498 (89.73) |
Ex-smoker | 179 (24.45) | 40 (3.47) | 86 (25.98) | 16 (2.88) |
Current smoker | 381 (52.05) | 83 (7.20) | 161 (48.64) | 41 (7.39) |
Smoking cessation attempted | ||||
No | 103 (19.22) | 37 (31.90) | 34 (14.29) | 15 (27.78) |
Yes | 433 (80.78) | 79 (68.10) | 204 (85.71) | 39 (72.22) |
Successful smoking cessation | ||||
No (not or less than 6 mo) | 374 (67.63) | 80 (66.67) | 159 (64.90) | 40 (71.43) |
Yes (more than 6 mo) | 179 (32.37) | 40 (33.33) | 86 (35.10) | 16 (28.57) |
Alcohol status | ||||
Non-drinker | 82 (11.20) | 357 (30.99) | 52 (15.66) | 165 (29.73) |
Past-drinker | 34 (4.64) | 116 (10.07) | 13 (3.92) | 59 (81.94) |
Current-drinker | 616 (84.15) | 679 (58.94) | 267 (80.42) | 331 (59.64) |
Cigarettes/d6 | 16.95 (7.99) | 12.51 (38.04) | 16.17 (6.99) | 9.57 (6.05) |
Packs year6 | 16.42 (12.16) | 6.08 (6.33) | 14.89 (9.75) | 6.08 (5.18) |
FTND6 | 3.52 (2.39) | 2.29 (2.28) | 3.33 (2.18) | 2.59 (2.35) |
Difference (95% CI) per one grade increase in socio-economic status |
||||||
---|---|---|---|---|---|---|
Sibling + twin1 (n = 937 pairs) |
Monozygotic twin (n = 442 pairs) |
|||||
Smoking rate OR (95% CI) | Smoking amount/d2 (β± 95% CI) | Pack year3 (β± 95% CI) | Smoking rate OR (95% CI) | Smoking amount/d (β± 95% CI) | Pack year (β± 95% CI) | |
Education4 | 0.79 (0.62, 1.01) | -0.87 (-2.69, 0.95) | -2.05 (-4.74, 0.64) | 0.67* (0.51, 0.93) | -1.13 (-2.52, -0.42) | -2.90** (-4.77, -1.95) |
Income5 | 0.97 (0.77, 1.23) | 0.65 (-0.84, 2.14) | -0.38 (-2.72, 1.97) | 1.30 (0.96, 1.75) | -0.63 (-2.10, 0.12) | -0.08 (-2.12, 0.96) |
Occupation6 | 0.97 (0.80, 1.19) | -0.91 (-2.36, 0.54) | 0.74 (-1.44, 2.93) | 0.89 (0.69, 1.15) | -2.48** (-3.52, -1.44) | -8.70** (-10.29, -7.11) |
Adjusted for age, gender, alcohol status.
OR, odds ratio; CI, confidence interval.
1 Dizygotic twins and monozygotic twins.
2 Cigarettes/d (current smokers only).
3 Current smokers only.
4 Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher.
5 Per one-grade difference where grade I: ≤25% (<860 000 won/mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo).
6 Compared with manual labor.
* p<0.05,
** p<0.01.
Siblings + twins1 (n = 909 pairs) |
Monozygotic twins (n = 436 pairs) |
|||||
---|---|---|---|---|---|---|
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND2 (β± 95% CI) | Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND (β± 95% CI) | |
Education3 | 1.68 (0.79, 3.56) | 1.29 (0.68, 2.44) | -0.70* (-1.28, -0.11) | 1.16 (0.42, 0.97) | 0.45* (0.21, 0.97) | -0.18 (-0.25, 0.40) |
Income4 | 0.80 (0.44, 1.45) | 1.21 (0.70, 2.10) | 0.65* (0.15, 0.96) | 0.70 (0.25, 1.96) | 0.60 (0.28, 1.31) | 0.52* (0.09, 0.74) |
Occupation5 | 1.35 (0.73, 2.48) | 2.55** (1.50, 4.31) | -0.28 (-0.77, 0.22) | 0.53 (0.15, 1.92) | 1.17 (0.35, 3.84) | -1.29** (-1.80, -1.03) |
Adjusted for age, gender, alcohol status.
OR, odds ratio; CI, confidence interval; FTND, Fagerstrom test for nicotine dependence.
1 Dizygotic twins and monozygotic twins.
2 Measured for current smokers only.
3 Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher.
4 Per one-grade difference where grade I: ≤25% (< 860 000 won/ mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo).
5 Compared with manual labor.
* p<0.05,
** p<0.01.
Siblings+twins1 |
Monozygotic twins |
|||||
---|---|---|---|---|---|---|
Smoking rate OR (95% CI) | Smoking amount/d2 (β± 95% CI) | Pack year3 (β± 95% CI) | Smoking rate OR (95% CI) | Smoking amount/d (β± 95% CI) | Pack year (β± 95% CI) | |
Male | n=730 (365 pairs) | n=331 (165 pairs) | ||||
Education4 | 0.62** (0.45, 0.84) | -1.21 (-3.91, 1.49) | -2.00 (-6.78, 2.78) | 0.28** (0.18, 0.48) | -1.03 (-2.54, 0.48) | -2.99** (-4.81, -1.17) |
Income5 | 1.03 (0.77, 1.37) | -1.35 (-4.56, 1.86) | -6.55 (-12.35, 0.75) | 0.67 (0.37, 1.19) | -0.28 (-1.93, 1.37) | -0.85 (-2.87, 1.17) |
Occupation6 | 0.90 (0.69, 1.19) | -2.47 (-4.72, 0.22) | -2.66 (-7.19, 1.87) | 0.88 (0.43, 1.82) | -2.63** (-4.43, -0.83) | -6.75** (-8.96, -4.54) |
Female | n=1144 (572 pairs) | n=554 (277 pairs) | ||||
Education | 0.95 (0.59, 1.53) | -0.18 (-7.37, 7.23) | 1.81 (-6.03, 9.65) | 0.99 (0.63, 1.59) | -1.51 (-5.86, 2.84) | 0.07 (-6.04, 6.19) |
Income | 1.01 (0.70, 1.47) | -6.73 (-13.77, 0.31) | 5.05 (-2.75, 12.85) | 1.03 (0.70, 1.54) | -3.11 (-6.50, 0.28) | -3.19 (-6.91, 0.53) |
Occupation | 1.24 (0.90, 1.73) | -0.08 (-5.14, 4.98) | 1.07 (-4.20, 6.34) | 1.11 (0.79, 1.56) | -1.15 (-3.89, 1.59) | 2.79 (-1.40, 6.98) |
Adjusted for age, alcohol status.
OR, odds ratio; CI, confidence interval.
1 Dizygotic twins and monozygotic twins.
2 Cigarettes/d (current smokers only).
3 Current smokers only.
4 Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher.
5 Per one-grade difference where grade I: ≤25% (<860 000 won/ mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo).
6 Compared with manual labor.
*p<0.05,
** p<0.01.
Siblings+twins1 |
Monozygotic twins |
|||||
---|---|---|---|---|---|---|
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND2 (β± 95% CI) | Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND (β± 95% CI) | |
Male | n=682 (341 pairs) | n = 322 (161 pairs) | ||||
Education3 | 1.07 (0.63, 1.81) | 1.51 (0.93, 2.46) | -0.44 (-1.20, 0.32) | 1.10 (0.63, 1.94) | 0.77 (0.49, 1.22) | -0.37 (-0.82, 0.08) |
Income4 | 0.85 (0.54, 1.35) | 0.85 (0.56, 1.30) | 0.04 (-0.52, 0.61) | 0.89 (0.52, 1.41) | 0.83 (0.55, 1.24) | 0.62 (-0.26, 1.50) |
Occupation5 | 1.00 (0.66, 1.53) | 1.62* (1.09, 2.42) | -0.80 (-2.09, 0.49) | 1.18 (0.72, 1.94) | 1.13 (0.76, 1.67) | -0.72* (-1.31, -0.13) |
Female | n=1136 (568 pairs) | n=550 (275 pairs) | ||||
Education | 1.75 (0.40, 7.69) | 1.07 (0.25, 4.51) | -0.64 (-3.07, 1.79) | 0.99 (0.30, 3.27) | 0.78 (0.49, 1.22) | -0.13 (-1.11, 0.85) |
Income | 1.36 (0.41, 4.54) | 1.61 (0.35, 7.41) | 1.55 (-0.96, 4.06) | 0.98 (0.37, 2.59) | 0.83 (0.56, 1.24) | -0.46 (-1.07, 0.15) |
Occupation | 0.67 (0.26, 1.69) | 0.57 (0.18, 1.80) | 1.15 (-0.67, 2.97) | 1.29 (0.55, 3.02) | 1.13 (0.77, 1.67) | -0.44 (-1.09, 0.21) |
Adjusted for age, alcohol status.
OR, odds ratio; CI, confidence interval; FTND, Fagerstrom test for nicotine dependence.
1 Dizygotic twins and monozygotic twins.
2 Current smokers only.
3 Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher.
4 Per one-grade difference where grade I: ≤25% (< 860 000 won/mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo).
5 Compared with manual labor.
* p<0.05,
**p<0.01.
Subject characteristics | All pairs (Sibling + twins) |
Monozygotic twins |
||
---|---|---|---|---|
Male | Female | Male | Female | |
No. of participants | 732 (38.85) | 1152 (61.15) | 332 (37.39) | 556 (62.61) |
Age (y) | 39.72 (8.21) | 39.04 (7.83) | 39.15 (7.50) | 37.78 (7.05) |
Education level | ||||
Middle school or lower | 96 (13.11) | 155 (13.45) | 46 (13.86) | 53 (9.53) |
High school | 338 (46.17) | 583 (50.61) | 146 (43.98) | 290 (52.16) |
College or higher | 298 (40.71) | 414 (35.94) | 140 (42.17) | 213 (38.31) |
Equivalized household income | ||||
≤25 |
177 (24.18) | 272 (23.61) | 55 (16.57) | 85 (15.29) |
25 - 75 |
434 (59.29) | 665 (57.73) | 210 (63.25) | 324 (58.27) |
>75 |
120 (16.39) | 215 (18.66) | 67 (20.18) | 147 (26.44) |
Occupation | ||||
Manual | 278 (37.98) | 200 (17.36) | 118 (35.54) | 98 (17.63) |
Non-manual | 400 (54.64) | 414 (35.94) | 193 (58.13) | 218 (39.21) |
Others |
54 (7.38) | 538 (46.70) | 21 (6.33) | 240 (43.17) |
Smoking status | ||||
Non-smoker | 172 (23.50) | 1025 (88.98) | 84 (25.38) | 498 (89.73) |
Ex-smoker | 179 (24.45) | 40 (3.47) | 86 (25.98) | 16 (2.88) |
Current smoker | 381 (52.05) | 83 (7.20) | 161 (48.64) | 41 (7.39) |
Smoking cessation attempted | ||||
No | 103 (19.22) | 37 (31.90) | 34 (14.29) | 15 (27.78) |
Yes | 433 (80.78) | 79 (68.10) | 204 (85.71) | 39 (72.22) |
Successful smoking cessation | ||||
No (not or less than 6 mo) | 374 (67.63) | 80 (66.67) | 159 (64.90) | 40 (71.43) |
Yes (more than 6 mo) | 179 (32.37) | 40 (33.33) | 86 (35.10) | 16 (28.57) |
Alcohol status | ||||
Non-drinker | 82 (11.20) | 357 (30.99) | 52 (15.66) | 165 (29.73) |
Past-drinker | 34 (4.64) | 116 (10.07) | 13 (3.92) | 59 (81.94) |
Current-drinker | 616 (84.15) | 679 (58.94) | 267 (80.42) | 331 (59.64) |
Cigarettes/d |
16.95 (7.99) | 12.51 (38.04) | 16.17 (6.99) | 9.57 (6.05) |
Packs year |
16.42 (12.16) | 6.08 (6.33) | 14.89 (9.75) | 6.08 (5.18) |
FTND |
3.52 (2.39) | 2.29 (2.28) | 3.33 (2.18) | 2.59 (2.35) |
Difference (95% CI) per one grade increase in socio-economic status |
||||||
---|---|---|---|---|---|---|
Sibling + twin |
Monozygotic twin (n = 442 pairs) |
|||||
Smoking rate OR (95% CI) | Smoking amount/d |
Pack year |
Smoking rate OR (95% CI) | Smoking amount/d (β± 95% CI) | Pack year (β± 95% CI) | |
Education |
0.79 (0.62, 1.01) | -0.87 (-2.69, 0.95) | -2.05 (-4.74, 0.64) | 0.67 |
-1.13 (-2.52, -0.42) | -2.90 |
Income |
0.97 (0.77, 1.23) | 0.65 (-0.84, 2.14) | -0.38 (-2.72, 1.97) | 1.30 (0.96, 1.75) | -0.63 (-2.10, 0.12) | -0.08 (-2.12, 0.96) |
Occupation |
0.97 (0.80, 1.19) | -0.91 (-2.36, 0.54) | 0.74 (-1.44, 2.93) | 0.89 (0.69, 1.15) | -2.48 |
-8.70 |
Siblings + twins |
Monozygotic twins (n = 436 pairs) |
|||||
---|---|---|---|---|---|---|
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND |
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND (β± 95% CI) | |
Education |
1.68 (0.79, 3.56) | 1.29 (0.68, 2.44) | -0.70 |
1.16 (0.42, 0.97) | 0.45 |
-0.18 (-0.25, 0.40) |
Income |
0.80 (0.44, 1.45) | 1.21 (0.70, 2.10) | 0.65 |
0.70 (0.25, 1.96) | 0.60 (0.28, 1.31) | 0.52 |
Occupation |
1.35 (0.73, 2.48) | 2.55 |
-0.28 (-0.77, 0.22) | 0.53 (0.15, 1.92) | 1.17 (0.35, 3.84) | -1.29 |
Siblings+twins |
Monozygotic twins |
|||||
---|---|---|---|---|---|---|
Smoking rate OR (95% CI) | Smoking amount/d |
Pack year |
Smoking rate OR (95% CI) | Smoking amount/d (β± 95% CI) | Pack year (β± 95% CI) | |
Male | n=730 (365 pairs) | n=331 (165 pairs) | ||||
Education |
0.62 |
-1.21 (-3.91, 1.49) | -2.00 (-6.78, 2.78) | 0.28 |
-1.03 (-2.54, 0.48) | -2.99 |
Income |
1.03 (0.77, 1.37) | -1.35 (-4.56, 1.86) | -6.55 (-12.35, 0.75) | 0.67 (0.37, 1.19) | -0.28 (-1.93, 1.37) | -0.85 (-2.87, 1.17) |
Occupation |
0.90 (0.69, 1.19) | -2.47 (-4.72, 0.22) | -2.66 (-7.19, 1.87) | 0.88 (0.43, 1.82) | -2.63 |
-6.75 |
Female | n=1144 (572 pairs) | n=554 (277 pairs) | ||||
Education | 0.95 (0.59, 1.53) | -0.18 (-7.37, 7.23) | 1.81 (-6.03, 9.65) | 0.99 (0.63, 1.59) | -1.51 (-5.86, 2.84) | 0.07 (-6.04, 6.19) |
Income | 1.01 (0.70, 1.47) | -6.73 (-13.77, 0.31) | 5.05 (-2.75, 12.85) | 1.03 (0.70, 1.54) | -3.11 (-6.50, 0.28) | -3.19 (-6.91, 0.53) |
Occupation | 1.24 (0.90, 1.73) | -0.08 (-5.14, 4.98) | 1.07 (-4.20, 6.34) | 1.11 (0.79, 1.56) | -1.15 (-3.89, 1.59) | 2.79 (-1.40, 6.98) |
Siblings+twins |
Monozygotic twins |
|||||
---|---|---|---|---|---|---|
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND |
Attempted smoking cessation OR (95% CI) | Successful smoking cessation (≥6 mo) OR (95% CI) | FTND (β± 95% CI) | |
Male | n=682 (341 pairs) | n = 322 (161 pairs) | ||||
Education |
1.07 (0.63, 1.81) | 1.51 (0.93, 2.46) | -0.44 (-1.20, 0.32) | 1.10 (0.63, 1.94) | 0.77 (0.49, 1.22) | -0.37 (-0.82, 0.08) |
Income |
0.85 (0.54, 1.35) | 0.85 (0.56, 1.30) | 0.04 (-0.52, 0.61) | 0.89 (0.52, 1.41) | 0.83 (0.55, 1.24) | 0.62 (-0.26, 1.50) |
Occupation |
1.00 (0.66, 1.53) | 1.62 |
-0.80 (-2.09, 0.49) | 1.18 (0.72, 1.94) | 1.13 (0.76, 1.67) | -0.72 |
Female | n=1136 (568 pairs) | n=550 (275 pairs) | ||||
Education | 1.75 (0.40, 7.69) | 1.07 (0.25, 4.51) | -0.64 (-3.07, 1.79) | 0.99 (0.30, 3.27) | 0.78 (0.49, 1.22) | -0.13 (-1.11, 0.85) |
Income | 1.36 (0.41, 4.54) | 1.61 (0.35, 7.41) | 1.55 (-0.96, 4.06) | 0.98 (0.37, 2.59) | 0.83 (0.56, 1.24) | -0.46 (-1.07, 0.15) |
Occupation | 0.67 (0.26, 1.69) | 0.57 (0.18, 1.80) | 1.15 (-0.67, 2.97) | 1.29 (0.55, 3.02) | 1.13 (0.77, 1.67) | -0.44 (-1.09, 0.21) |
Values are presented as number (%). FTND, Fagerstrom test for nicotine dependence. Dizygotic twins and monozygotic twins. < 860 000 won/mo. 860 000-1 730 000 won/mo. >1 730 000 won/mo. Included housewives, students, unemployed, retired. Current smokers only.
Adjusted for age, gender, alcohol status. OR, odds ratio; CI, confidence interval. Dizygotic twins and monozygotic twins. Cigarettes/d (current smokers only). Current smokers only. Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher. Per one-grade difference where grade I: ≤25% (<860 000 won/mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo). Compared with manual labor.
Adjusted for age, gender, alcohol status. OR, odds ratio; CI, confidence interval; FTND, Fagerstrom test for nicotine dependence. Dizygotic twins and monozygotic twins. Measured for current smokers only. Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher. Per one-grade difference where grade I: ≤25% (< 860 000 won/ mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo). Compared with manual labor.
Adjusted for age, alcohol status. OR, odds ratio; CI, confidence interval. Dizygotic twins and monozygotic twins. Cigarettes/d (current smokers only). Current smokers only. Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher. Per one-grade difference where grade I: ≤25% (<860 000 won/ mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo). Compared with manual labor. *
Adjusted for age, alcohol status. OR, odds ratio; CI, confidence interval; FTND, Fagerstrom test for nicotine dependence. Dizygotic twins and monozygotic twins. Current smokers only. Per one-grade difference where grade I: middle school or lower, grade II: high school, grade III: college or higher. Per one-grade difference where grade I: ≤25% (< 860 000 won/mo), grade II: 25%-75% (860 000-1 730 000 won/mo), grade III: >75% (>1 730 000 won/mo). Compared with manual labor. **