Adjusted odds ratios for smoking initiation between baseline and follow-up among the Massachusetts youth cohort*
| Probability that never-smokers at baseline will have initiated smoking at follow-up | ||
|---|---|---|
| OR (95% CI) | p Value | |
| *Cohort includes only youths who had never smoked or puffed at baseline. | ||
| †Local youth-access regulations were classified as (1) strong if the town had strong enforcement (regulations allowing fines or requiring licences, and average compliance checks of two per vendor per year) and strong marketing restrictions (restrictions on both free-standing cigarette displays and vending machine marketing); (2) medium if the town had either strong enforcement or strong marketing restrictions; and (3) weak if the town had neither strong enforcement nor strong marketing restrictions. | ||
| Policy variables | ||
| Strength of youth-access regulations† | ||
| Weak | 1.00 | |
| Medium | 0.93 (0.671 to 1.286) | 0.655 |
| Strong | 0.89 (0.610 to 1.308) | 0.562 |
| Individual-level variables | ||
| Age at baseline (continuous) | 1.37 (1.271 to 1.484) | <0.001 |
| Sex | ||
| Male | 1.00 | |
| Female | 0.98 (0.789 to 1.222) | 0.871 |
| Race/ethnicity | ||
| Non-hispanic white | 1.07 (0.772 to 1.490) | 0.678 |
| Other | 1.00 | |
| Rebelliousness (continuous) | 3.43 (2.020 to 5.817) | <0.001 |
| Baseline smoking status | ||
| Nonsusceptible non-smoker | 1.00 | |
| Susceptible non-smoker | 3.06 (2.275 to 4.107) | <0.001 |
| Household-level variables | ||
| At least one parent smokes | ||
| No | 1.00 | |
| Yes | 1.77 (1.298 to 2.420) | 0.001 |
| Education of adult informant | ||
| Not a college graduate | 1.00 | |
| College graduate | 0.95 (0.726 to 1.253) | 0.732 |
| Household income | ||
| ⩽$50 000 or unreported | 1.00 | |
| >$50 000 | 1.15 (0.894 to 1.487) | 0.273 |
| Town-level variables | ||
| Town population | ||
| <20 000 | 1.00 | |
| 20 000–50 000 | 0.73 (0.534 to 1.002) | 0.051 |
| >50 000 | 0.80 (0.528 to 1.222) | 0.306 |
| Percentage of town “yes” vote on question 1 (continuous) | 1.00 (0.984 to 1.015) | 0.937 |
| Percentage of town residents who are white (continuous) | 1.00 (0.992 to 1.015) | 0.599 |
| Percentage of town residents who are aged <18 years (continuous) | 0.97 (0.947 to 1.001) | 0.060 |