Progression to established smoking* among Massachusetts youth cohort† by strength‡ of local restaurant smoking regulation and potential confounding variables
| Progressed* (%) | Did not progress* (%) | Unadjusted OR§ (95% CI) | Adjusted OR¶ (95% CI) | |
|---|---|---|---|---|
| *Progression to established smoking was defined as smoking 100 or more cigarettes in one’s life. Data are weighted to account for baseline probability of respondent selection. | ||||
| †Cohort includes only youths who were not established smokers (that is, had smoked fewer than 100 cigarettes in their life) at baseline. | ||||
| ‡Strength of local restaurant smoking regulation was defined as strong if it banned smoking completely in all restaurants with no variances, medium if it banned smoking but allowed variances or restricted smoking to enclosed, separately ventilated areas, and weak if it required only designated smoking areas or did not restrict smoking at all. | ||||
| §Unadjusted odds ratio for progression to established smoking. Odds ratio is derived from generalised estimating equations (GEE) logistic regression model that accounts for clustering of responses within towns. Data are weighted to account for baseline probability of respondent selection. | ||||
| ¶Odds ratios are adjusted for all other variables in the table. | ||||
| **Odds ratio corresponding to each 10 percentage point increase. | ||||
| CI, confidence interval; OR, odds ratio. | ||||
| Main predictor variable | ||||
| Strength‡ of local restaurant smoking regulation | ||||
| Weak‡ | 8.0 | 92.0 | 1.00 | 1.00 |
| Medium‡ | 8.2 | 91.8 | 1.04 (0.73 to 1.47) | 1.06 (0.70 to 1.62) |
| Strong‡ | 4.9 | 95.1 | 0.59 (0.38 to 0.92) | 0.39 (0.24 to 0.66) |
| Individual level variables | ||||
| Age at baseline (years) | ||||
| 12–14 | 5.0 | 95.0 | 1.00 | 1.00 |
| 15–17 | 10.5 | 89.5 | 2.21 (1.63 to 3.00) | 1.15 (0.80 to 1.66) |
| Sex | ||||
| Male | 8.1 | 91.9 | 1.00 | 1.00 |
| Female | 7.0 | 93.0 | 0.86 (0.63 to 1.16) | 0.73 (0.51 to 1.03) |
| Race/ethnicity | ||||
| Non-Hispanic white | 7.4 | 92.6 | 1.00 | 1.00 |
| Other | 7.6 | 92.4 | 1.02 (0.63 to 1.65) | 1.43 (0.81 to 2.53) |
| Smoking status | ||||
| Non-susceptible non-smoker | 2.2 | 97.8 | 1.00 | 1.00 |
| Susceptible non-smoker | 6.8 | 93.2 | 3.27 (1.89 to 5.66) | 3.42 (1.96 to 5.99) |
| Puffer | 10.9 | 89.1 | 5.45 (3.19 to 9.33) | 4.22 (2.40 to 7.43) |
| Experimenter | 29.4 | 70.6 | 18.6 (11.6 to 29.7) | 13.6 (8.03 to 23.0) |
| Current smoker | 54.4 | 45.6 | 53.2 (28.8 to 98.3) | 42.8 (21.1 to 86.9) |
| Peer smoking | ||||
| No close friend smokes | 4.2 | 95.8 | 1.00 | 1.00 |
| At least one close friend smokes | 17.5 | 82.5 | 4.91 (3.68 to 6.54) | 1.99 (1.38 to 2.89) |
| Exposure to anti-smoking messages at school | ||||
| No | 8.9 | 91.1 | 1.00 | 1.00 |
| Yes | 7.1 | 92.9 | 0.79 (0.56 to 1.11) | 0.70 (0.47 to 1.03) |
| Household level variables | ||||
| Household smoking | ||||
| No adult smoker in household | 5.8 | 94.2 | 1.00 | 1.00 |
| Adult smoker in household | 11.2 | 88.8 | 2.04 (1.52 to 2.73) | 1.47 (1.05 to 2.05) |
| Education of adult informant | ||||
| Not college graduate | 8.6 | 91.4 | 1.00 | 1.00 |
| College graduate | 6.4 | 93.6 | 0.73 (0.53 to 0.99) | 0.96 (0.68 to 1.36) |
| Household income | ||||
| ⩽$50000 | 7.5 | 92.5 | 1.00 | 1.00 |
| >$50000 | 7.2 | 92.8 | 0.97 (0.67 to 1.40) | 1.15 (0.76 to 1.72) |
| Town level variables | ||||
| Percentage of town residents who are college graduates** | – | – | 0.94 (0.86 to 1.02) | 0.80 (0.60 to 1.06) |
| Percentage of town “yes” vote on Question 1** | – | – | 0.95 (0.82 to 1.11) | 1.33 (0.80 to 2.23) |
| Percentage of town residents who are white** | – | – | 1.13 (1.05 to 1.22) | 1.29 (1.06 to 1.56) |
| Percentage of town residents who are youths** | – | – | 0.77 (0.54 to 1.10) | 0.78 (0.52 to 1.17) |
| Number of restaurants | ||||
| ⩾5 | 7.4 | 92.6 | 1.00 | 1.00 |
| <5 | 8.3 | 91.7 | 1.13 (0.75 to 1.69) | 0.71 (0.41 to 1.23) |
| Population | ||||
| <20000 | 8.8 | 91.2 | 1.00 | 1.00 |
| 20000–50000 | 6.7 | 93.3 | 0.74 (0.53 to 1.04) | 0.67 (0.43 to 1.03) |
| >50000 | 6.8 | 93.2 | 0.74 (0.53 to 1.03) | 0.90 (0.50 to 1.61) |