Studies that demonstrated a disruption of commercial distribution to minors (1991–2011)
| Studies (listed by first author) | Design and setting | Impact on commercial distribution* | Association with youth tobacco use* |
| Altman23 | A 3-year randomised controlled study of community mobilisation and merchant education without enforcement involving four Arizona communities | The intervention produced a temporary reduction in purchases by 7th graders but not by 9th and 11th graders | During the period when 7th graders made fewer purchases smoking was reduced by 23% in this age group. Neither purchases nor smoking were reduced among older youth. |
| Chaloupka47 | Cross-sectional survey of impact of vending machine restrictions and statewide compliance checks across states (US) | Violation rates varied by state | Aggressive statewide approaches to measuring compliance coupled with higher retailer compliance reduced youth smoking. Complying with Synar Amendment requirements of 80% compliance and aggressive enforcement would reduce smoking by 18%. |
| Dent48 | Cross-sectional evaluation of the impact of varying compliance rates across 75 communities in Oregon | Inexplicably, higher violation rates were associated with less reliance on commercial sources among 8th graders | Reliance on commercial sources was related to smoking among 8th graders. Increasing compliance from 0% to 100% would be associated with a 7.9% reduction in past 30-day smoking for 11th graders and a 4.1% reduction in daily smoking. The 11th graders in communities with lower illegal sales rates had increased reliance on social sources but decreased smoking. |
| DiFranza49 | A 2-year single community study of enforcement of a local ordinance in Massachusetts | Violations dropped from 75% to 16% | Smoking declined by 31% among youth ages 12–19 years |
| DiFranza35 | Longitudinal study of state enforcement in Texas | Reliance on commercial sources among middle school students declined from 20.8% to 7% | The prevalence of smoking in middle school declined from 20.0% to 14.8%. High school students showed no decline in commercial access and no decline in the prevalence of smoking. |
| DiFranza50 | National longitudinal study of the impact of 7 years of state enforcement (US) | Violation rates decreased across all states across the study period | For each 2% increase in compliance, the prevalence of smoking in 10th graders decreased by 1% |
| Forster36, Chen51 | A 7-year randomised controlled study of 14 Minnesota communities with half assigned to enact and enforce a law | Violation rates improved in both groups. Decreased commercial source for the most recent cigarette. Recent purchases declined by a relative 51.6% among all youths. | Approximate 28% decrease in daily smoking, approximate 25% decrease in weekly smoking, approximate 22% decrease in monthly smoking. The impact on daily smoking persisted for 5 years, at which point the control communities caught up in terms of implementing restrictions. |
| Jason41, Jason42 | An 8-year single community study of enforcement of a local ordinance in Illinois | Violation rates decreased from 19% to 3%. Only 6% of current smokers reported commercial access in town. | Experimentation decreased from 46% to 23% and regular use from 16% to 5% |
| Jason52 | Controlled cross-sectional study of two towns with good enforcement and three Illinois towns with poor enforcement | Fewer youths in the enforcement communities obtained cigarettes from stores (27.8%) than in the non-enforcement communities (46.5%) | Regular smoking was 8.1% in the intervention communities and 15.5% in the non-enforcement communities. Lifetime use of smokeless tobacco was 8.7% vs 16.7%. |
| Jason53 | A 3-year randomised controlled study of four Illinois communities with strong access and possession laws versus four with moderate enforcement of access land possession laws | Violation rates improved from 21% to 4% in the intervention communities and from 31% to 17% in the control communities. Children in the intervention community felt it was harder to get tobacco. | For Caucasians, over 3 years tobacco use increased by 15.6% in the control communities and by 4.1% in the intervention communities. Cigarettes smoked per month increased from 0.4 to 27.4 in the control group and from 1.1 to 6.3 in the intervention group, a difference of 81%. |
| Levinson33 | A 9-month study of local enforcement in a Colorado community | Usual way of getting cigarettes from stores decreased from 22.6% to 3.5%. Current smokers who had ever bought cigarettes decreased from 26.4% to 13.8%. Fewer smokers carried cigarettes most days. Smokers carried fewer cigarettes at a time. It became harder to ask strangers for cigarettes. | Smoking in the past 30 days decreased from 22% to 15% among 14–15 year olds |
| Perla54, Cummings39 | Cross-sectional analysis of 12 New York communities originally randomised to enforcement or control groups | Reliance on commercial sources declined by 54% in communities with violation rates <20% and by 43% in communities with violation rates >20% | Violation rates <20% were associated with a 44% reduction in smoking 20 or more of the past 30 days |
| Pokorny55 | Cross-sectional analysis of the impact of the density of non-compliant retailers in Illinois communities | Retailer violation rates varied across towns | Violation rates influenced initiation but not continuation |
| Ross56, Powell57 | National cross-sectional analysis of differences in state violation rates (US) | Violation rates varied across states | Ross: Lower violation rates, vending machine restrictions and graduated fines each reduced smoking prevalence and intensity. Powell: The impact of access policies on youth smoking was mediated through peers. |
| Staff22 | A 9-month non-randomised evaluation of the impact of merchant education only in a single region and control (Sydney, Australia) | Male students rated it harder to purchase from petrol stations after the intervention | The likelihood of current smoking was reduced by almost half in 7th year students only, OR=0.54. The likelihood of being a daily smoker versus occasional or non-smoker was OR=0.39 for 7th year only. No impact on years 8–11. |
| Staff43 | A 5-year evaluation of an extraordinarily weak enforcement programme in a single area with no control group (Sydney, Australia) | Compliance was 66%. A slight decrease in the proportion of students who had purchased tobacco from small stores (19.2% vs 16.8%). There was a small increase in perceived difficulty of purchasing, but at follow-up 82% of students rated it easy or very easy to purchase tobacco from small stores. | There was a slight increase in the number of never smokers (OR=1.16). There was no change in the number of current smokers. |
| Tutt37, Tutt38 | A 9-year longitudinal controlled study of aggressive enforcement in New Zealand | Compliance was 96-100%. Attempts to purchase tobacco in the intervention area declined by 73.6% between 1993 and 2002. | The prevalence of monthly smoking among students in years 7–12 was reduced by 50% from 26% to 13% |
| Verdonk-Kleinjan58 | A 4-year prospective study of enacting a new law in The Netherlands | The proportion of youth that smoked and bought their own tobacco fell from 13.5% to 6.4% | The prevalence of smoking among youth 13–15 years old fell from 20.3% to 7.4% |
| Widome40 | A 3-year longitudinal study of local enforcement of Minnesota laws | Commercial purchases decreased and reliance on social sources increased | Youths who had no commercial access were less likely to progress to heavier smoking |
↵* All reported findings were statistically significant.