Results of multinomial logistic regression analysis examining associations of changes in smoking behaviours with demographics and health-related behaviours
| Variables | Affected and quit | Affected and reduced smoking amount | Affected and changed smoking behaviour in other ways* | Unaffected but quit smoking | ||||
| OR | (95% CI) | OR | (95% CI) | OR | (95% CI) | OR | (95% CI) | |
| Monthly household income (unit: million KRW)† | ||||||||
| <1 (US$845) | 1.98 | (1.54 to 2.54) | 2.23 | (1.98 to 2.51) | 1.69 | (1.43 to 2.00) | 1.37 | (1.11 to 1.68) |
| (1–1.99) | 1.29 | (1.05 to 1.58) | 1.56 | (1.40 to 1.72) | 1.58 | (1.37 to 1.82) | 0.93 | (0.77 to 1.12) |
| (2–2.99) | 1.05 | (0.87 to 1.26) | 1.36 | (1.24 to 1.49) | 1.25 | (1.11 to 1.41) | 0.99 | (0.85 to 1.14) |
| (3–3.99) | 1.02 | (0.86 to 1.21) | 1.16 | (1.06 to 1.27) | 1.13 | (0.99 to 1.29) | 0.98 | (0.85 to 1.14) |
| ≥4 (US$3380) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Age (years) | ||||||||
| 19‒29 | 0.73 | (0.53 to 1.00) | 0.76 | (0.63 to 0.90) | 1.09 | (0.85 to 1.40) | 0.96 | (0.71 to 1.29) |
| 30‒39 | 0.57 | (0.43 to 0.76) | 0.63 | (0.54 to 0.74) | 0.99 | (0.78 to 1.24) | 0.71 | (0.55 to 0.92) |
| 40‒49 | 0.62 | (0.48 to 0.82) | 0.62 | (0.53 to 0.72) | 1.02 | (0.81 to 1.28) | 0.54 | (0.42 to 0.69) |
| 50‒59 | 0.63 | (0.49 to 0.82) | 0.67 | (0.58 to 0.78) | 1.16 | (0.94 to 1.44) | 0.60 | (0.48 to 0.76) |
| 60‒69 | 0.88 | (0.69 to 1.12) | 0.83 | (0.72 to 0.95) | 1.17 | (0.94 to 1.46) | 0.89 | (0.71 to 1.12) |
| ≥70 | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Education level | ||||||||
| ≤Middle school | 0.98 | (0.80 to 1.21) | 1.47 | (1.31 to 1.65) | 1.55 | (1.32 to 1.81) | 0.90 | (0.74 to 1.09) |
| Mid. sch. to Univ. | 0.90 | (0.78 to 1.04) | 1.28 | (1.19 to 1.39) | 1.32 | (1.18 to 1.46) | 0.85 | (0.75 to 0.96) |
| ≥University | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Marital status | ||||||||
| Single | 0.75 | (0.63 to 0.89) | 1.00 | (0.92 to 1.09) | 1.05 | (0.94 to 1.18) | 0.62 | (0.53 to 0.74) |
| Married | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Number of household members | ||||||||
| One | 0.90 | (0.71 to 1.15) | 0.79 | (0.71 to 0.89) | 1.00 | (0.86 to 1.15) | 1.08 | (0.88 to 1.33) |
| Two | 1.09 | (0.93 to 1.26) | 0.88 | (0.81 to 0.95) | 1.06 | (0.95 to 1.18) | 1.12 | (0.98 to 1.28) |
| Three or more | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Type of community | ||||||||
| City (urban) | 1.16 | (1.02 to 1.32) | 1.05 | (0.98 to 1.12) | 0.99 | (0.91 to 1.08) | 1.16 | (1.03 to 1.30) |
| Town (rural) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| High-risk alcohol drinking | ||||||||
| Yes | 0.82 | (0.72 to 0.93) | 0.79 | (0.74 to 0.85) | 1.11 | (1.02 to 1.21) | 0.76 | (0.67 to 0.86) |
| No | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Physical activity | ||||||||
| No | 0.92 | (0.80 to 1.05) | 1.00 | (0.93 to 1.07) | 0.97 | (0.89 to 1.07) | 0.94 | (0.84 to 1.06) |
| Yes | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Self-reported stress level | ||||||||
| High | 0.74 | (0.65 to 0.85) | 0.94 | (0.88 to 1.01) | 1.19 | (1.09 to 1.30) | 0.77 | (0.69 to 0.87) |
| Low | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Experience of depression | ||||||||
| Yes | 0.98 | (0.74 to 1.28) | 1.23 | (1.09 to 1.40) | 1.37 | (1.16 to 1.61) | 0.98 | (0.76 to 1.26) |
| No | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
| Number of chronic diseases‡ | ||||||||
| Two or more | 1.12 | (0.94 to 1.34) | 1.06 | (0.96 to 1.16) | 1.05 | (0.92 to 1.19) | 1.46 | (1.25 to 1.71) |
| One | 1.11 | (0.97 to 1.27) | 1.04 | (0.97 to 1.11) | 1.05 | (0.95 to 1.15) | 1.09 | (0.97 to 1.24) |
| Zero | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) | 1.00 | (Ref) |
*Other changes including ‘switched to cheaper brands’, ‘switched to e-cigarettes’, ‘switched to non-cigarette tobacco products’ and ‘other’.
†P for trend <0.001 of monthly household income as an ordinal variable: for ‘affected and quit’, p<0.001; for ‘affected and reduced smoking amount’, p<0.001; for ‘affected and changed smoking behaviour in other ways’, p=0.326; for ‘unaffected but quit smoking’, adjusted for all other variables.
‡Doctor-diagnosed high blood pressure, diabetes, hypoglycaemic, arthritis, asthma, allergic rhinitis or atopic dermatitis.