Article Text

A systematic review of interventions for preventing tobacco sales to minors
  1. Lindsay F Stead,
  2. Tim Lancaster
  1. Imperial Cancer Research Fund General Practice Research Group, Department of Primary Health Care, University of Oxford, Institute of Health Sciences, Oxford, UK
  1. Lindsay Stead, Imperial Cancer Research Fund General Practice Research Group, Department of Primary Health Care, University of Oxford, Institute of Health Sciences, Old Road, Headington, Oxford OX3 7LF, UK; lindsay.stead{at}dphpc.ox.ac.uk

Abstract

OBJECTIVE To assess the effectiveness of interventions to reduce underage access to tobacco by deterring shopkeepers from making illegal sales.

METHOD Systematic literature review.

DATA SOURCES The Cochrane Tobacco Addiction group specialised register and Medline. Studies of interventions to alter retailer behaviour were identified. The terms used for searching combined terms for smoking and tobacco use with terms for minors, children or young people, and retailers, sales or commerce.

STUDY SELECTION Studies in which there was an intervention with retailers of tobacco, either through education about, or enforcement of, local ordinances. The outcomes were changes in retailer compliance with legislation (assessed by test purchasing), changes in young people's perceived ease of access to tobacco products, and changes in smoking behaviour. Controlled studies with or without random allocation of retail outlets or communities, and uncontrolled studies with pre- and post intervention assessment, were included.

DATA EXTRACTION Two reviewers assessed studies for inclusion. One extracted data with checking by the second.

DATA SYNTHESIS The results were synthesised qualitatively, with greater weight given to controlled studies. Thirteen of 27 included studies used controls.

RESULTS Giving retailers information was less effective in reducing illegal sales than active enforcement and/or multicomponent educational strategies. No strategy achieved complete, sustained compliance. In three controlled trials, there was little effect of intervention on youth perceptions of access or prevalence of smoking.

CONCLUSIONS Interventions with retailers can lead to large decreases in the number of outlets selling tobacco to youths. However, few of the communities studied in this review achieved sustained levels of high compliance. This may explain why there is limited evidence for an effect of intervention on youth perception of ease of access to tobacco, and on smoking behaviour.

  • smoking prevention
  • sales to minors
  • young people
  • systematic review

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Controlling access is an established strategy for reducing consumption of substances harmful to health, in particular tobacco, alcohol, and illicit drugs. Of adolescents who try smoking more than a third become daily smokers in secondary school.1 Successful restriction of young people's access to tobacco products could help prevent them from developing this addiction. Accordingly, many countries prohibit tobacco sales to minors.

Although young people perceive difficulties in obtaining cigarettes as a deterrent to tobacco use,2 poor compliance with access laws is well documented.3 In most surveys, underage young people report little difficulty when illegally purchasing cigarettes.4-8 In the USA a 1998 survey found that 90% of 10th grade students (ages 15–16 years) would find it “fairly easy” or “very easy” to get cigarettes.9 In a 1997 survey, 30% of high school smokers reported cigarette purchase in the previous month, of whom less than a third had been asked for proof of age.10 In England a 1996 survey suggested that 25% of all secondary school children had tried to buy cigarettes in a shop in the last year. Only 38% had been refused at least once.11

Furthermore, commercial sources of tobacco are not the only way in which young people obtain products.3 They may also get cigarettes from parents, siblings, friends, and by theft. Reducing access to commercial sources could lead to increased use of such sources. In determining policy it is important to know both how best to restrict access, and the likely effect of successful restriction on youth tobacco consumption.

Objective

The aim of this review was to assess the effectiveness of reducing underage access to tobacco products by deterring shopkeepers from illegal sales. We asked three questions:

(1)
Does intervention with retailers, by education, active enforcement of laws, or combinations of strategies lead to decreased sales to minors? Is there evidence that any of the strategies is superior to the others?
(2)
Do reduced sales of tobacco to minors lead to a decrease in their self reported ease of access?
(3)
Do reduced sales of tobacco to minors reduce prevalence of tobacco use?

Data sources

We used the Cochrane Tobacco Addiction Group specialised register which has been developed by systematic sensitive searches of Medline and PsycLit and handsearching of journals, includingTobacco Control. We looked for studies involving restrictions on sales to minors or sales from vending machines, and interventions with retailers related to compliance with legislation. We searched Medline for any other controlled or uncontrolled evaluations. The search strategy is specified in an additional table on the Web site.

Study selection

TYPES OF STUDIES

We considered studies of measures to improve compliance with laws restricting youth access to retail sales of tobacco, using one of these study designs:

(1)
Controlled trials randomising retail outlets, communities or geographical regions.
(2)
Controlled trials without randomisation allocating retail outlets, communities or geographical regions.
(3)
Time series studies.
(4)
Uncontrolled before and after studies.

We excluded uncontrolled studies with post intervention measurements only.

TYPES OF PARTICIPANTS

We evaluated strategies which targeted retailers to reduce tobacco use by minors. Minors were defined by the legal age limit in the communities studied.

TYPES OF INTERVENTION

We considered education, law enforcement, community mobilisation, or combinations of strategies that aimed to deter retailers from selling tobacco to minors.

TYPES OF OUTCOME MEASURES

We considered the outcomes of:

(1)
Illegal tobacco sales, assessed by attempted purchase by young people.
(2)
Perceived ease of access to cigarettes by young people.
(3)
Prevalence of tobacco use among young people. We accepted self reports of tobacco use.

Data extraction

The review was conducted in four stages:

(1)
One reviewer prescreened reports for relevance.
(2)
Two reviewers assessed relevant studies independently. To be included they had to meet all the criteria listed above for study design, type of participant and intervention and outcomes assessed.
(3)
One reviewer extracted, and the second checked, data from included studies.
(4)
Studies were combined using qualitative narrative synthesis.

We chose narrative, rather than quantitative, synthesis because we expected heterogeneity in the study designs, type of interventions and outcomes measured.

Data synthesis

DESCRIPTION OF INCLUDED STUDIES

A table containing full details of each study including setting, design, intervention and outcomes is available on theTobacco Control web site.

We identified 27 studies that met the inclusion criteria. Of these, 13 used some form of control group. In six studies the store was the unit of randomisation.12-18 One study identified the retailers who made illegal sales to minors at baseline.18 These retailers were then randomly allocated to receive a warning letter threatening prosecution, or no letter. One carried out test purchasing around one school and not around another.19 20 Six studies compared interventions in different communities. Forster and colleagues' tobacco policy options for prevention (TPOP) study randomised 14 Minnesota communities after stratification on baseline variables.21-23 Altman and colleagues allocated two pairs of Monterey communities on the basis of a coin toss.24Cummings and colleagues assigned six matched pairs of communities to intervention or control status; within the intervention communities the stores were randomly allocated to different schedules of enforcement checks.13 The other three community studies in Massachusetts,25 San Diego26 27 and Sydney, Australia28 compared the intervention communities with a control community in which similar baseline and follow up assessments were conducted, but without random assignment. In Massachusetts,25 intervention communities were those in which active enforcement of tobacco sales regulations was intended. The control communities were not planning active enforcement, although by the end of the study some enforcement was being conducted.

The remaining uncontrolled studies compared rates of illegal sales or smoking behaviour before and after an intervention. In some, only the outlets that allowed purchase at baseline were followed up. In Ontario, Canada, a series of interventions were implemented in neighbouring health units and the follow up ranged from two weeks to 21 months.29 In Oregon, implementation occurred in eight communities at different time points.30

TYPES OF INTERVENTION

The main interventions were: education about legal requirements; notification of the results of compliance checks; warning of enforcement, and implementation of enforcement by police or health officials. Some studies tested different frequencies of enforcement activity, and different channels of information. In some the intervention included the introduction of new legislation or local ordinances such as a licensing system or a formal requirement for compliance checking.

The TPOP campaign in Minnesota aimed “to make tobacco access by youth a salient community issue, to change local ordinances . . .to change retailers' and other adults' practices...and to promote enforcement of tobacco age-of-sale laws”. The campaign used a direct action community organising model so communities differed in the specific ordinances introduced. These included an increased licence fee for tobacco outlets, penalties for the vendor and the clerk, a requirement for unannounced compliance checks, and bans on vending machines and self service displays. Other studies also included elements to raise community awareness and support.16 17 24 26-28 30-35

In some studies, the intervention had to be modified because of local attitudes. Altman and colleagues were unable to bring about enforcement action because of legal concern about the use of “sting” operations and an unwillingness to prosecute clerks.24

In most studies there was dissemination of information to retailers about their legal obligations, including reminders of the age at which purchase was legal, that proof of age should be required before sale, or that warning notices should be displayed. Usually this information was posted, but sometimes mass media channels were used.

OUTCOME ASSESSMENT

Twenty five studies assessed retailer compliance with the law using test purchasers. Most studies focused on “over the counter” sales but some also assessed ease of purchase from vending machines. Some distinguished between sales in shops with behind the counter or locked displays and self service.36 One study37 investigated vending machine purchases only.

Eight studies assessed the effect of an intervention on the smoking behaviour of underage youth. Five of these were controlled trials. Three assessed retailer behaviour as well,21 24 25 while one assessed only smoking behaviour.28 One assessed smoking prevalence in both areas but retailer behaviour only in the intervention area.19 The three uncontrolled studies measured smoking behaviour before and after a change in enforcement practice. Two assessed retailer behaviour as well.32 33 38 Six studies also asked underage smokers where they obtained their cigarettes and how difficult it was to buy them.

EXCLUDED STUDIES

Two surveys have assessed the effect of the tobacco industry sponsored voluntary compliance programme “It's the Law”.40 41 We did not include them because there was no baseline assessment of retailers before they joined the programme. The authors found no evidence that those participating in the scheme were less likely than other retailers to make illegal sales. Reasons for excluding three other studies42-44 are given in an additional Web table.

METHODOLOGICAL QUALITY OF INCLUDED STUDIES

As we considered a heterogeneity of study designs, we made no attempt at statistical meta-analysis. However, we gave greater weight in our synthesis to the three controlled studies that measured the behaviour of retailers and minors in the community.21 24 25 In uncontrolled studies, background secular change may be incorrectly attributed to an intervention.

Although randomisation by community is a less biased method for assessing the effect of intervention, statistical analysis of such studies should address the issue of clustering of behaviour within communities. Clustering usually increases the required sample size.45 Few of the included studies directly addressed this issue: another reason why formal meta-analysis could be misleading.

A further methodological concern is the measurement of outcome. In most studies compliance was judged by a single purchase attempt. However, when multiple purchase attempts were made, the estimates of compliance were lower when retailers were classified as non-compliant only if they never sold. Junck and colleagues34 found that compliance after intervention was 74% on the basis of a single purchase attempt at each store, but only 45% if three attempts were made. This bias may overestimate compliance rates in studies using only one purchase attempt. The age of the assessor also affects measurement of compliance. DiFranza and colleagues showed that 16–17 year olds were more successful than younger children, and girls were more successful than boys.41 Sales rates may also be underestimated if test purchasers act differently from true underage purchasers. All the studies which gave details noted that the youths engaged in testing were to state their true age if challenged, and to say that the cigarettes were for their own use.

Results

DOES INTERVENTION WITH RETAILERS LEAD TO DECREASED SALES TO MINORS?

Eleven controlled trials assessed the effect of an intervention on illegal sales, measured by compliance checks (table 1). Six found that intervention reduced the level of illegal sales compared to the control group.12 14 18 24-27

Table 1

Results from controlled trials

Active enforcement was used in three of the successful interventions. In Chicago,12 sales fell marginally in the month after all merchants who had sold cigarettes received a warning, but enforcement produced a much larger fall in sales rates. Media coverage of the study at one point during the follow up period caused a further substantial drop in sales in all groups. This study showed that two monthly enforcement visits were more effective than four and six monthly schedules, giving a sales rate of 19% in the final six months of the intervention. In Harlem14 enforcement produced a substantial decrease in sales, not found after an educational visit alone. However, the rate still fell only to 47%. In Massachusetts,25 compliance rates improved from 35% to 82% in the intervention communities and from 28% to 45% in the control areas.

Three interventions without enforcement produced greater improvements in compliance than in control areas. Project Trust in San Diego26 27 used multicomponent community and retailer education with personal visits. Sales fell significantly between pre- and postintervention measurement in four out of six intervention areas and in no control area. The sales rate was reduced from 70% to 32%, an effect sustained at six month follow up. In Monterey,24 education and community organisation eliminated successful test purchases by the end of a three year project in two communities compared to a 39% sales rate in the comparison communities. In Sydney18 warning letters threatening prosecution to retailers who had made illegal sales led to a second offence rate of 31%, compared to 60% among those not warned.

Other controlled trials did not find a difference. The comprehensive community approach used in Minnesota reduced successful over the counter purchases in intervention communities from 36.7% to 3.1%, but the net change was not significantly different from the control communities where the rate fell from 41% to 8.8%.21 In Santa Clara16 17 there was no additional effect of mailed or personally delivered educational materials without enforcement. However, the community and merchant education media had some short term effect, with sales rates reduced from 74% to 39%.

In Erie Country there was no effect of education alone46or active enforcement.13 In the second study the lack of effect could have been because all stores were sent letters warning of possible random checks. The news of “sting” operations also spread rapidly to the non-enforcement communities. A study in New South Wales, Australia15 used education and the threat of enforcement. Youths old enough to buy cigarettes, but looking younger, were used for compliance checks so the outcome was requiring proof of age before making a sale. There was an overall improvement from 17% to 43% in the proportion of retailers requiring such proof, but no difference between intervention and control retailers.

All the uncontrolled studies (table 2) showed reduction in illegal sales following intervention, but the size of the pre- and post-difference was variable, and not always consistent across communities.47 There was some evidence that effects declined over time.30 38 In Oregon, advising retailers whether they had or had not complied with the law at a test purchase had an effect.30 In Solana County31 a merchant education programme had such a limited effect that a second phase of police enforcement was initiated. This reduced over the counter sales from 74% to 24%. The highest compliance rates were in Woodridge (over 95%)32 and Leominster (84%)38 which used enforcement, and in Manly34 (86%), Ontario29 (94%), and Wisconsin48 (82%) which did not. The lowest was 49% for baseline non-compliers in Cook County.49

Table 2

Results from uncontrolled trials

In the study of vending machines, a locking device policy resulted in fewer locations selling cigarettes to minors than a policy of no restriction.37 However, the authors concluded that it was probably less effective than the major policy alternative, a ban on vending machines.

DO REDUCED SALES OF TOBACCO TO MINORS LEAD TO A REDUCTION IN MINORS' SELF REPORTED EASE OF ACCESS?

Six studies assessed perceived ease of access. In three, intervention was associated with decreased test sales. In Monterey24 self reported recent purchase of tobacco was less frequent among seventh grade students (ages 12–13) in the intervention than in the control communities. In the other two grades there were large baseline differences in the proportion reporting a purchase in the last three months, so longitudinal changes were difficult to interpret. However, at the final follow up recent purchase was significantly less common among intervention community ninth grade students (ages 14–15). After intervention in Woodridge,3269% of students said that the law would make cigarettes harder to obtain. In 1996 more Woodridge smokers felt it was difficult or moderately difficult to get cigarettes than smokers from another community (20 v 14.3%, not significant).32 In Massachusetts25 despite an effect of intervention on sales there was no difference in perceived ease of access. There were significant falls in the proportion who had tried to buy tobacco in the previous six months, and increases in those who were refused at least half the time. Since these occurred in all communities they could not be attributed to the active enforcement programme. There were also similar changes across intervention and control communities in reported source of cigarettes. Fewer youths bought tobacco in their own city or town and more bought it elsewhere or had someone buy it for them.

In Minnesota,21 the proportion who perceived high availability decreased in the intervention communities while increasing in the control communities, despite similar levels of retailer compliance. The proportion of adolescents reporting at least one purchase attempt in the previous month declined in the intervention communities while it increased in the control communities. The authors suggested that these changes might be attributable to the community awareness and mobilisation campaigns that were a part of the intervention.

In Sydney28 there was a significant reduction in the proportion of male students who rated purchasing cigarettes from petrol stations as “easy” or “very easy” postintervention, but no other significant changes for the six categories of purchase source. In Everett39 more students reported that retailers asked for proof of age. Neither of these studies directly assessed retailer behaviour. In Gateshead few children reported being refused, with no change over time.19 20

DO REDUCED SALES OF TOBACCO TO MINORS DECREASE PREVALENCE OF TOBACCO USE?

Three of five controlled trials found an effect of intervention on youth smoking behaviour. Altman and colleagues24 found a lower smoking prevalence in those who were in seventh grade at baseline, but the effect was not sustained at the end of the 32 month study. There were no significant differences among the other age groups.

In Minnesota, there was a lower rate of increase in all measures of smoking prevalence in seven areas with a comprehensive community based intervention than in seven control communities. The net difference in prevalence was significant for daily, but not weekly or monthly, smoking.21 They concluded that refusals by sellers at the time of purchase attempts by young people did not account for the lower adolescent smoking rates seen in the intervention communities, since all communities showed increases in compliance. Other components of the intervention may have changed young people's behaviour. Businesses in the intervention communities were more likely to post warning notices and to store cigarettes behind the counter.

Staff and colleagues assessed a community intervention in Sydney with education of retailers and local publicity, measuring smoking behaviour and reported ease of purchase but not illegal sales.28There was an effect of intervention only in the youngest students.

Two studies did not find evidence of change in smoking behaviour. In Massachusetts25 there was no difference in the rate of change of prevalence of “any tobacco use” or “daily tobacco use” between the intervention and control communities. The rate of “current tobacco use” rose marginally in the intervention communities but remained stable in controls, with borderline significance for the comparison between group trends. In Gateshead, an intervention of test purchases in the intervention area resulted in full compliance and hence no prosecutions, although children in the area reported buying cigarettes with ease. There was no change in smoking prevalence.19

In the light of these findings, three uncontrolled studies should be interpreted with caution. Two reported a decrease in smoking prevalence in students associated with a reduction in illegal sales in single intervention communities.32 33 38 39 50 In Woodridge the proportion of regular smokers among seventh and eighth grade students (ages 12–14 years) fell from 16% to 5%. In this study32 access was very successfully restricted, and possession of tobacco by a minor was also an offence. Longer term assessments in this community using older youths showed higher rates of sales, although still below 20%.33 A survey in 1996 found a lower proportion of smokers among Woodridge students than students from a community not conducting regular enforcement.50 In Leominster there was a fall in smoking prevalence in three out of four age groups.38 In Everett39 there was no significant change in overall reported tobacco use after introduction of a local ordinance, but there was a significant decrease among girls.

Conclusions

This review provides evidence about the relative effectiveness of different interventions for reducing tobacco sales by retailers. Simply giving information to retailers about the law is not effective. DiFranza and colleagues showed that merchant participation in voluntary compliance programmes was low.40 41 There is evidence that interventions to educate retailers can improve compliance, but the successful interventions used a variety of strategies, including personal visits and mobilising community support.24

Enforcement, or warnings of it, generally had an effect on retailer behaviour. Sustaining compliance requires regular enforcement, and the existing evidence suggests reduced effectiveness if checking occurs much less than 4–6 times a year.12 The penalty for infringement may also be important, although there is little direct evidence of the relative deterrent effect of different penalties. If fines for offenders are low, retailers may become inured to the threat of a prosecution, diminishing the effect of warnings or prosecutions. Removal of a license to sell tobacco could be more effective, if the licensing itself is strictly monitored.18 Imposing too harsh a penalty may, however, be counterproductive if community attitudes are not supportive. In one study using enforcement, judges were inclined to give suspended sentences because they felt that imposing a heavy fine or criminal record on the clerks making the sale was inappropriate.31 Enforcement may produce a backlash against tobacco control activities if the value of reducing sales has not been adequately publicised. A graduated system of penalties from a warning to a fine and then loss of licence may be most appropriate where legal systems allow it. The combination of enforcement and fines on youth users was associated with high compliance rates in Woodridge, but punishing the user may not gain widespread acceptance.51

Retailer interventions may not work if neighbouring districts have discordant policies. Retailers who make illegal sales argue that minors will simply go elsewhere, depriving them of revenue without benefiting the community.52 Uniform enforcement policies may help retailers to comply by reassuring them that their competitors will do the same. Similarly, fitting locks to vending machines is probably less effective than banning them.37

The main methodological problem in evaluating retailer interventions is that assessment of retailer behaviour during compliance checks does not show whether smoking behaviour by minors has changed, or even how easy it is for them to buy tobacco. Retailers may be able to identify “test” purchasers, especially if they know or suspect that checks are being made. “Real” purchasers may be known to the sales clerks, may lie about their age or may behave differently. If retailers are aware of the possibility of compliance checks they may sell only to young people they know. Young people may also change their source, by going to another community or by asking someone else to make the purchase for them.25 Measuring changes in self reported ease of access to tobacco is important to show that an intervention has had an impact on purchasing behaviour. If minors do not perceive that buying tobacco has become more difficult, then it is unlikely that they have changed their use of tobacco. Conversely, a change in smoking behaviour can most confidently be attributed to a change in retailer behaviour if the intermediate outcome of a change in perception of ease of access has also been observed. This is an important message for future research in this area.

There are a number of problems in drawing conclusions about the effectiveness of interventions with retailers for reducing youth tobacco use. In particular, effectiveness can only be assessed if tobacco sales are reduced. If some retailers continue to sell, a channel of access will exist. Many of the communities studied achieved large decreases in sales, but none achieved complete, sustained compliance. Hence it is not surprising that there is only limited evidence from controlled trials that reducing the ease with which underage youth can purchase cigarettes will reduce their use of tobacco. Some uncontrolled studies, notably Woodridge, have reported impressive reductions in youth smoking behaviour in association with interventions achieving high compliance. This might suggest that there is a threshold level of compliance above which access can be effectively reduced. This hypothesis needs testing prospectively. The findings from Massachusetts25 suggest that, if there is such a threshold, it must be greater than 80%; density of vendors may be another determinant of availability. The challenge for future research on the effects of restriction of underage sales is to ensure effective implementation of the intervention. Translating access restriction from research to practice is a further challenge. In the USA, despite federal legislation in 1992 (the Synar Amendment) requiring all states to enact and enforce a law to prohibit sale of tobacco to minors, surveys have shown no change from 1992 to 1997 in the proportion (almost 90%) of 10th grade students who believed that they can easily obtain tobacco products.53

A further limitation of current research is that it is largely confined to more developed countries. The effectiveness and feasibility of retailer interventions will depend on the attitudes and available resources in different societies. With the acceleration of tobacco use in the developing world there is a particular need for cost effective interventions to prevent uptake of smoking by the youth of these societies.

Acknowledgments

A version of this review has been published in the Cochrane Library. Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this, or other Cochrane reviews of interventions for tobacco control, please send it tolindsay.stead{at}dphpc.ox.ac.uk. Information about the Cochrane Collaboration and subscribing to the Cochrane Library is available fromwww.cochrane.org. We wish to acknowledge the support for the Cochrane Tobacco Addiction Group from the UK NHS Research and Development Programme, and the Imperial Cancer Research Fund. We thank the editors of Tobacco Control for agreeing to publish this version.

References

WEBSITE EXTRA

Additional tables appear on the Tobacco Control website www.tobaccocontrol.com

Supplementary materials

  • Table 1 Details of studies included in the review
     
     
     
     
     
     
     
     
    StudyParticipantsInterventionOutcomes
    Alberta (Compliance for Kids), Abernathy.47

    Pre-post study, no control group. Three communities, Canada

    Stratified random sample of retail outlets: community A n=30; community B n=40; community C (all retail outlets) n=7. Different sample pre- and post-test. Legislation and education. Introduction of a city bylaw combined with a retailer education programme. In communities A&B materials were delivered by mail, in C they were delivered by a health unit employee. Illegal sales: single test purchase attempt by < 16 years at baseline and 3 months.

    Retailers surveyed by telephone on knowledge of the Tobacco Restraint Act and stated willingness to sell to minors if accompanied by parental note.

    Bristol, Naidoo and Platts.54

    Pre-post study, no control group. City, UK.

    100 tobacconists randomly selected from Yellow Pages at pre-test and 50 at post-test. Retailer education and publicity. Letter sent to all tobacconists clarifying law and offering publicity material. Press conference publicising results of purchase attempts. Illegal sales: single test purchase by one of four children "well under" 16 years at baseline and 12 months. Retailers interviewed about knowledge of law.
    Chicago, Jason et al.12

    Controlled trial with stratified randomisation of stores within ethnic areas.

    Urban communities (white, Latino and African American neighbourhoods), USA.

    120 stores in 3 ethnic areas were identified. 7 stores went out of business during study and are excluded. Education and enforcement: Test of different schedules. Purchase attempts were made monthly, beginning in December 1993. After April 1994 assessment, merchants who sold cigarettes were notified and warned of programme of inspections. Other merchants given congratulatory note. All given educational materials. At enforcement visits fines of $200.

    Interventions: Enforcement every 2, 4, and 6 months. Control: No enforcement.

    Illegal sales: assessors judged to be 16- 17 years who gave correct age if challenged. Single attempt at each store each month. Generally unaccompanied. Different assessor each month.

    Monthly compliance tests continued for stores not due for enforcement checks. Period of intervention 11 months.

    Cook County, McDermott et al.49 Pre-post study, no control group. Suburban area, Illinois, USA. 347 retailers; 129 stores selling at baseline retested  Education and warning. Copy of state law and warning letter sent to all vendors selling at baseline (compliers sent congratulatory letter, not revisited). Illegal sales: single purchase attempt by 14- 17 years accompanied by adult supervisor at baseline and 3 month follow up.
    Erie County 1987, Skretny et al.46Controlled trial with random allocation of stores to condition. Buffalo, New York, USA. Retail outlets (supermarkets, convenience stores, and pharmacies) Intervention n=60; control n=58. Retailer education. Stores mailed educational package with letter citing the New York state law and requesting assistance in observing the law. Warning signs and tip sheet for educating employees. Illegal sales: single test purchase by one of 7 minors, 14- 16, 2 weeks after intervention (no baseline assessment).
    Erie County 1995, Cummings et al.13

    Controlled trial, 6 pairs of communities non-randomly assigned. Stores within communities randomly assigned to enforcement schedules. 12 socioeconomically varied communities, New York, USA.

    All retail outlets selling tobacco over the counter in each community (excluding bars). 319 outlets at follow up. Enforcement compared to warning only. All licensed stores sent reminder of law and warning of random enforcement December 1994. Stores allocated to 1, 2 or 3 enforcement checks over 8 month period. Violators fined, compliers sent congratulatory letter. Illegal sales: test purchase attempt by one of 23 minors aged 15- 17 (some conducted enforcement as well as compliance checks) gave true age if asked. At follow up 98% of stores checked 3 times using different assessors. Same 3 minors used in paired communities. Smoking behaviour: not assessed.

     

    Everett, Hinds.39Pre-post study, no control group. One community, Snohomish, Washington, USA. Retailers (target of intervention)

    10th grade high school students (pre-intervention n=221, post-intervention n=279). Mean age 15 years.

    Legislation. New local ordinance required signs, restricted vending machines, required proof of age for purchases, required a local licence, introduced penalties for violations. Smoking behaviour: survey of students before and 1 year after ordinance. Perceived access: Purchasing behaviour and reports of retailers asking for proof of age.
    Gateshead, Bagott et al.19 20

    Controlled study. Catchment areas for 2 schools, Gateshead, UK.

    14- 15 year old students at 2 schools (117 at baseline in intervention school, 107 at control school). Retailers in intervention area: 13 shops surveyed, 70% of those close to intervention school. Enforcement (intended). Test purchasing was carried out around the intervention school, prosecution intended for offenders. The retailers around the control school were not approached. No illegal sales were made. Smoking behaviour: survey of year 10 students pre- and post-intervention. Self reported source of cigarettes and difficulty in purchasing. Illegal sales assessed only as part of the intervention, not as part of assessment. Trading standards officer was in shop during purchase attempt by child aged # 13 years.
    Harlem, Gemson et al.14

    Controlled trial with random assignment of stores

    Urban community, New York City, USA.

    152 stores licensed to sell tobacco (excludes 29 no longer selling tobacco at end of study). Enforcement or education. Enforcement: stores violating regulations fined. Education: single visit; explanation of law, leaflets. Control: no intervention. There was media coverage of the result of the baseline survey of the enforcement stores. Illegal sales: test purchases by African American male or female aged 12- 14. Asked to purchase a single cigarette, if refused second student would ask for a packet. Assessment at baseline, 6 month (violators fined) and 1 year. Assessment and enforcement checks were combined.
    Leominster, DiFranza et al.38Pre-post study, no control group. Single community, Massachusetts, USA. Retailers (target). Students grade 7- 12, 501 at baseline, 633 in total in 2 post intervention surveys. Education plus enforcement. Merchant education followed by enforcement. Violators warned and repeat offenders fined. Compliers received letters of commendation. Smoking behaviour: change in self reported smoking prevalence in 3 cross sectional surveys. Illegal sales: attempted purchases on 3 occasions, 11, 15, and 19 months after regulations adopted, by males and females of different ages. No baseline before introduction of regulations.
    Manly, Junck et al.34Pre-post study, no control group. Single community, New South Wales, Australia. All 54 tobacco retailing outlets not licensed for alcohol in Manly. Assessed at baseline, 3 months, and 10 months. Community intervention including media coverage and public forum. Retailer education: Police delivered kit and verbally congratulated those not selling at baseline. Public Health Unit sent official warning letter to those selling at baseline. Illegal sales: test purchase by 14- 16 years visiting in pairs, truthful responses. At baseline and 3 months, outlets visited up to three times if they refused sale. At 10 months, outcome based on single attempt.
    Massachusetts, Rigotti et al.25Controlled trial. Three intervention communities planned active enforcement of similar regulations; three matched control communities not planning enforcement. USA. Every retail outlet in each community. All students in grades 9- 12 aged under 18 and resident in city or town where they attended school were surveyed at baseline and annually for 2 years. Enforcement. All six local health departments distributed written information. Health departments of intervention communities began testing and penalising violators with an escalating series of warning and fines. Encouraged to test 4 times/year, with more frequent testing for non-compliant retailers.

    In control communities no compliance testing was planned.

    Illegal sales: test purchases (independent of compliance testing in intervention communities) made by girls aged 16. Truthful responses. Single attempt per store, at 6 month intervals. OTC and vending machine purchases attempted.

    Smoking behaviour: prevalence of tobacco use in past 30 days, prevalence of any tobacco use, and of regular daily use. Access measured as difficulty reported by those who had tried to buy tobacco in previous 6 months: bought/tried to buy tobacco. Hardly ever refused/ refused at least half the time.

    Monterey, Altman et al.24 Controlled trial with allocation of communities by coin toss. Two pairs of communities, California, USA. All retailers in each community assessed. All students in selected grades surveyed. Comprehensive community intervention with retailer education. Retail outlets contacted directly on multiple occasions. Aimed to raise awareness, educate and transmit community norms. Illegal sales: test purchase by 13- 17 years on multiple occasions over 34 months. Truthful responses. Smoking behaviour: initial survey of 7th, 9th, 11th graders. Grade cohorts surveyed at four time points.
    New South Wales, Schofield et al.15Controlled trial with random assignment of stores. New South Wales, Australia. Retailers within 50 km identified. 300 retail outlets randomised, 272 checked for compliance, 217 completed both surveys. Education or education and threat of enforcement. All retailers surveyed pre- and postintervention.. Minimal intervention (education): information from public health unit. Maximal intervention (education and threat of enforcement); plus warning of enforcement; plus visit. Illegal sales: single test purchase using 18 years assessed as looking younger, who wore school uniform, at baseline and 2 month postintervention. Each assessor did approx. 50 checks. Compliance was requiring proof of age. Knowledge and attitudes of retailers assessed by survey. Smoking behaviour: not assessed.
    Ontario, Dovell et al.29Pre-post study, no control group. Two neighbouring health units. Two interventions were implemented sequentially in one (KFL&A) with assessment over 21m and one in the other (H&PE) with assessment over 2 weeks. Canada. Stores in the health unit areas. Different numbers assessed at each time point. Retailer education. In KFL&A: 1. (between base and 6 months) - media events, public flyers, results of purchase attempts; 2. (between 6 months and 21 months) Targeted intervention sending information kits and advising retailers of compliance, also federal intervention.

    In H&PE: Federal intervention - kits sent by Health Canada with letter saying inspector might call. Assessment 1 week later.

    Illegal sales: single test purchase at baseline, 6 months and 21 months by pairs of 13- 14 years. One watched while other requested cigarettes.
    Oregon (Project SixTeen), Biglan et al.30 55 Multiple baseline time series. Eight communities in Oregon, USA. Retailers in eight communities. Programme first used in two while baseline assessment continued in two more, then replicated in a further four. Community intervention and education, positive reinforcement. Components: mobilising community support; merchants education; changing consequences to clerks for selling (reminder) or not selling (gift token reward); publicity; feedback. Implemented by a community coordinator. Illegal sales: test purchase attempts (underage possession illegal) by 16- 17 years at 2 week intervals over approx. 6 months.
    Perth, Mawkes et al.35 Pre-post study, no control group. Areas near schools in urban areas of Perth, Western Australia. Tobacco merchants within 2 km of 12 secondary schools surveyed at baseline in 1992 (230 outlets) and again in 1994 (284 outlets). Comprehensive, including education, enforcement and community action. State wide activities. Materials sent to retailers. Prosecutions, or warning letters if prosecution impossible. Illegal sales: single purchase attempts by pairs of 15- 16 years (same pair used for most areas at follow up). At baseline, but not follow up, children could say cigarettes were for parents if initially refused.
    San Diego Project TRUST, Keay, Wildey et al.26 27 Controlled trial with cluster allocation of stores. Six communities in California, USA. Retailers in six low income, ethnically diverse communities. Data from 260 stores at pre- and post-test and 236 at 6 month follow up. Education and community awareness. Face to face education of retailers combined with community and media strategies. Included video for training sales assistants. Managers of stores which sold at baseline also received 10 min discussion from Environmental Health Field inspectors. Duration of intervention 1 year. Control: no intervention. Illegal sales: single purchase or purchase attempt (in two communities ringing up of the cigarettes constituted a "sale") by 70 teens aged 12- 17 years. Assessment at baseline and 1 year (1 month after conclusion of intervention), and 6 months later.
    Santa Clara, Altman et al.16 17 Controlled trial with random allocation of stores to different contact. California, USA. 412 stores selling cigarettes over the counter and 30 with vending machines. At 6 months post-test n=408, at 1 year n=97 from a stratified random sample. Retailer education (as supplement to community intervention). Components: 1. Community education through mass media and presentations to community groups; 2. Direct education with merchants who sold tobacco - stores were randomly allocated to one of 3 variants of this component: (i) no personal contact, (ii) mailed information, (iii) visits from project staff with education kit; 3. Contact with CEOs of major chains and franchises. Illegal sales: single test purchases by 14- 16 year olds (18 assessors). Attempt to use same assessor for pre- and 6 month post-test.
    Solana County, Feighery et al.31 Pre-post study, no control group. Four communities in one county, California, USA. The initial intervention was modelled on that used in Santa Clara. Random 50% sample of stores in three cities and all in a fourth city surveyed at pretest (n=169). 104 revisited at post-test 2, and a further 41 visited for the first time. Education only, followed by enforcement

    Education packages mailed to retailers. Pretest results widely publicised. Second phase; local police departments requested to carry out stings - underage police cadets attempted purchases and citations issued. Results (34% sales) were publicised in local media. Local judges did not always willing to sentence or fine those issued with citations.

    Illegal sales. Test purchases by 14- 16 year olds. Single attempt at pre-test and two post-tests.
    St Paul, Forster et al.37Pre-post study, no control group. Minnesota, USA. Random sample of businesses with vending machines. Baseline data for 95 of a possible 237 machines; complete data for 77. Vending machine locks. New ordinance which required locking devices on all cigarette vending machines in city. Illegal sales: test purchase by females 15 years before implementation and 3 and 12 months postimplementation.
    Stirling, Campbell.56

    Pre-post study, no control

    Scotland, UK.

    Convenience sample of 41 outlets surveyed at baseline. Intervention delivered to those selling. Resurvey of these and a further 26 outlets not initially visited 7 months later. Warning: immediately after a successful purchase at baseline, verbal warning given by Trading Standards Officer. Followed up by letter. Illegal sales: test purchase by 11- 15 year olds.
    Sydney 1992, Chapman et al.18Controlled trial with randomisation of outlets to warning letter. Six suburban areas, Australia. Pre-intervention (T1) "stings" at a sample of outlets (n=255). Postintervention (T2) stings carried out at 2 months (n=244). Retailers found selling cigarettes at T1 were randomly allocated to receive or not receive a warning letter (intervention n=50, control n=49). Threat of enforcement. Letter warning of another "sting" and threatening prosecution sent to 50% of retailers selling at T1. Also media publicity about an undercover buying operation. Illegal sales: single test purchase by 12- 13 year olds who visited stores in pairs and gave truthful answers at T1 and T2, approx. 2 months after warning letter.
    Sydney 1995, Staff et al.28 Controlled study. Two distinct areas of city, Australia All retailers targeted, 357 education kits distributed. Public and schools also targeted. Students at 13 public secondary schools surveyed. Retailer education and community awareness. Intervention area: "beat police" delivering education kits to retailers. Media articles, information in school newsletters. "Informers" line to identify non compliant retailers. Control area: no intervention. Illegal sales: not assessed. Smoking behaviour: baseline survey of students in years 7- 11. Follow up 6 months later. Smoking prevalence. Ease of purchase.
    TPOP (Tobacco Policy Options for Prevention), Forster et al.21- 23 Controlled trial with community randomisation. Fourteen rural communities, Minnesota, USA. All retail outlets, and students in grades 8- 10 in all communities. Comprehensive community intervention including new ordinances, community awareness, media campaigns, and compliance checks. All intervention communities introduced new ordinances, with a variety of provisions. Three control communities introduced new ordinances but these were weaker and less comprehensive. Illegal sales: test purchases, two attempts on successive days by 15 year old females. Smoking behaviour: in school survey of grades 8- 10 in 1993 and 1996. Never/monthly/weekly/daily smokers. Perceived access: ease of purchase; usual source; number of purchase attempts.
    Wisconsin, Schensky et al.48

    Pre-post study, no control group. Dane County, Wisconsin, USA.

    60 retailers surveyed at baseline and follow up. Retailer education and feedback. Retailers notified of the results of compliance test, given signage and offered training. Illegal sales: single test purchases by 12- 15 year olds in groups of 2- 3 who reported age honestly, at baseline and 12 months.
    Woodridge, Jason et al.32 33 50 Pre-post study, no control. Single community, Illinois, USA. All stores in Woodridge (19- 20 at baseline, 22- 30 at follow up assessments). Local students (680 at pretest, 639 at post-test). Legislation and enforcement. New ordinances, including licensing, enforcement, possession of cigarettes an offence. Education and media coverage. Legislation introduced May 1989. Quarterly compliance checking, compliers congratulated. Illegal sales: test purchases by 12- 17 year olds (age range changed over period). Assessments at 6 month intervals from August 1988 to December 1994. Smoking behaviour: surveys of local 7th and 8th graders in March 1989 and April 1991. In 1991 they were asked about perceived availability. Further survey in 1996.
    Illegal sales: test purchase attempt indicates that assessment procedure did not involve completion of purchase.
     
     
    Table 2 MEDLINE search strategy used to identify interventions to reduce tobacco sales to minors

     
     
    Smoking cessation OR tobacco OR cigar* OR SMOKING-CESSATION OR TOBACCO-USE-DISORDER OR TOBACCO OR NICOTINE OR TOBACCO-SMOKELESS OR SMOKING/ prevention-and-control , therapy , legislation-and-jurisprudence OR ((quit* OR stop* OR ceas* OR giv*) near smoking)
    AND
    adolescen* OR minors OR under()age OR student* OR (young near2 people) OR children OR juveniles OR girls OR boys OR teenager* OR teens OR child
    AND
    sale OR sales OR retail OR retailer* OR store OR stores OR sell OR selling OR shop OR shops OR tobacconist* OR vending OR vendor* OR merchant* OR COMMERCE/ legislation-and-jurisprudence

    Terms in capitals are MeSH headings. Last issue of Medline Express on Silverplatter searched was 1999/7. Additional searches of other databases did not retrieve any references to studies not retrieved from MEDLINE.


     
     

    Table 3 Relevant studies not meeting full inclusion criteria
     

    StudyDescriptionReason for exclusion
    DiFranza and Brown 1992.40 41Survey of tobacco retailers, undertaken in Massachusetts in 1991, to evaluate the efficacy of the Tobacco Institute�s "Its the Law" programme. Of the retailers surveyed only 4.5% (7) were participating in the programme. Most of these retailers were found to be willing to sell cigarettes to minors. Most of the retailers not participating in the programme (131/149) were also willing to sell cigarettes to minors. Post intervention only, comparing retailers participating with those not. 
    DiFranza et al 1996. 40 41Survey of tobacco retailers to evaluate the efficacy of the Tobacco Institute's "Its the Law" programme, undertaken in Massachusetts in 1994

    Of 480 purchase attempts, 240 were made from participating retailers. Participation did not lead to a significantly lower rate of illegal sales.

    Post intervention only, comparing retailers participating with those not.
    Lewis et al 1996.4242- 44Project SCAN (Stop Children�s Addiction to Nicotine) included three broad activities: 1. a public information campaign utilising the media, newsletters, and a speaker�s bureau; 2. distribution of sale to minor cards to all citizens to report on stores that illegally sell cigarettes to minors; 3. work with community leaders, voluntary organisations, businesses, and law enforcement officials to support and implement activities. Police officers delivered the package to merchants. This study did not include any preprogramme measurement.

     

    Lewis et al 1996. 42- 44Intervention was citation or commendation of clerks by citizens in a Wichita community coalition. Both alcohol and tobacco sales targeted.  No data on number of stores selling tobacco, or number in which intervention was delivered.
    Woodruff et al 1995. 42- 44Intervention to reduce sales of single cigarettes.Test purchasers were 19- 32, not underage youths.