Table 1 Baseline characteristics of the Massachusetts youth cohort, by smoking status at baseline and follow‐up*.
| Never‐smokers at baseline (n = 1986) | Non‐established smokers at baseline (n = 518) | |||||||
|---|---|---|---|---|---|---|---|---|
| All (%) | Status at follow‐up | p Value† | All (%) | Status at follow‐up | p Value† | |||
| Never‐smoker (%) | Initiator (%) | Non‐established (%) | Established (%) | |||||
| Policy variables | ||||||||
| Strength of youth‐access regulations‡ | ||||||||
| Weak | 24.9 | 24.0 | 28.4 | 28.8 | 26.8 | 34.9 | ||
| Medium | 46.5 | 47.2 | 43.6 | 46.3 | 48.2 | 40.6 | ||
| Strong | 28.6 | 28.8 | 28.0 | 0.174 | 24.9 | 25.1 | 24.6 | 0.191 |
| Individual‐level variables | ||||||||
| Age at baseline (years) | ||||||||
| 12–14 | 60.7 | 64.8 | 45.6 | 29.0 | 27.6 | 33.0 | ||
| 15–17 | 39.3 | 35.2 | 54.4 | 0.000 | 71.0 | 72.4 | 67.0 | 0.255 |
| Sex | ||||||||
| Male | 51.7 | 51.4 | 52.7 | 49.4 | 47.8 | 53.9 | ||
| Female | 48.3 | 48.6 | 47.3 | 0.637 | 50.7 | 52.2 | 46.1 | 0.238 |
| Race/ethnicity | ||||||||
| Non‐Hispanic white | 81.9 | 81.2 | 84.4 | 79.5 | 79.7 | 78.9 | ||
| Other | 18.1 | 18.8 | 15.6 | 0.145 | 20.5 | 20.3 | 21.2 | 0.839 |
| Rebelliousness | ||||||||
| Less rebellious (below mean) | 56.9 | 60.6 | 43.2 | 27.5 | 29.0 | 23.0 | ||
| More rebellious | 43.1 | 39.4 | 56.8 | 0.000 | 72.5 | 71.0 | 77.0 | 0.198 |
| Smoking status at baseline | ||||||||
| Non‐susceptible non‐smoker | 78.3 | 83.0 | 61.2 | |||||
| Susceptible non‐smoker | 21.7 | 17.0 | 38.8 | 0.000 | ||||
| Puffer (no whole cigarette) | 49.3 | 57.4 | 25.3 | |||||
| Other experimenter (1–99 cigarettes, not last 30 days) | 37.5 | 35.5 | 43.7 | |||||
| Current smoker (last 30 days) | 13.2 | 7.2 | 31.0 | 0.000 | ||||
| Household‐level variables | ||||||||
| At least one parent smokes | ||||||||
| No | 75.8 | 77.5 | 69.4 | 63.6 | 64.7 | 60.5 | ||
| Yes | 24.2 | 22.5 | 30.6 | 0.001 | 36.4 | 35.3 | 39.5 | 0.409 |
| Education of adult informant | ||||||||
| Not a college graduate | 52.3 | 52.0 | 53.6 | 63.6 | 64.7 | 60.5 | ||
| College graduate | 47.7 | 48.0 | 46.4 | 0.560 | 36.4 | 35.3 | 39.5 | 0.090 |
| Household income | ||||||||
| ⩽$50 000 or not reported | 39.5 | 40.0 | 37.9 | 46.6 | 46.5 | 46.9 | ||
| >$50 000 | 60.5 | 60.0 | 62.1 | 0.454 | 53.4 | 53.5 | 53.1 | 0.948 |
| Town‐level variables | ||||||||
| Town population | ||||||||
| <20 000 | 38.9 | 37.5 | 44.0 | 38.3 | 36.3 | 44.2 | ||
| 20 000–50 000 | 36.4 | 37.6 | 32.3 | 35.1 | 35.6 | 33.8 | ||
| >50 000 | 24.7 | 25.0 | 23.7 | 0.049 | 26.6 | 28.1 | 22.0 | 0.231 |
| Percentage of town “yes” vote on question 1 (mean) | 51.0 | 50.9 | 51.3 | 0.331 | 50.7 | 50.5 | 51.4 | 0.304 |
| Percentage of town residents who are white (mean) | 85.9 | 85.7 | 86.8 | 0.104 | 85.4 | 84.4 | 88.3 | 0.004 |
| Percentage of town residents who are aged 18 years (mean) | 24.6 | 24.7 | 24.4 | 0.187 | 24.2 | 24.3 | 24.2 | 0.781 |
*Cohort includes only youths who were not established smokers (ie, had smoked <100 cigarettes in their life) at baseline.
†p Value results from the χ2 statistic or F test statistic of one‐way analysis of variance.
‡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.