Authors' objectives

To determine the effectiveness of laws restricting youth access to cigarettes on the prevalence of smoking among teenagers.

Searching

MEDLINE was searched from 1985 to 2001. The search terms used were reported. In addition, the references of reviews and located articles were checked.

Study selection

Assessment of study quality

The authors did not state that they assessed validity.

Data extraction

The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction.

The different smoking measures used were pooled in two groups: 30-day smoking, which comprised 30-day smoking, weekly smoking and self-reported smoking; and regular smoking, which comprised daily smoking, frequent smoking and self-reported 'regular smokers'. For studies that used separate measurements for different age groups, arithmetic averages of the separate effects were used. Teenagers aged 18 years or older were excluded from the analysis.

Methods of synthesis

Results of the review

Eight studies (1 cohort study and 7 cross-sectional studies) met the inclusion criteria; these included at least 20 communities in total (number not stated for one study). Within the intervention communities, 15,446 participants were included at baseline and 16,586 at follow-up. Within the control communities, 9,401 participants were included at baseline and 10,431 at follow-up.

Relationship between merchant compliance and youth smoking.

There was no statistically-significant relationship (20 communities) between merchant compliance and 30-day (r=0.116, P=0.486) or regular (r=0.017, P=0.926) smoking prevalence. There was no evidence of a threshold effect after compliance reached a certain level (e.g. 90% in 3 studies). There was no evidence (18 communities) that an increase in merchant compliance was associated with a decrease in 30-day (r=0.294, P=0.237) or regular (r=0.274, P=0.287) smoking prevalence.

Effect of youth access programmes.

There was no significant difference in youth 30-day smoking prevalence in communities with youth access interventions, compared with control communities (5 studies; difference -1.5%, 95% confidence interval, CI: -6.0, 2.9). Four of the 5 studies reported the compliance rates; compliance exceeded 82% in the intervention community. For the outcome regular smoking, one study reported a 2.9% increase (P=0.08) in prevalence while another reported a -4.9% decrease (95% CI: -0.9, -0.7).

Authors' conclusions

Youth access interventions are not associated with a consistent positive effect on youth smoking prevalence. Furthermore, there was no evidence that increased compliance is associated with decreased prevalence.

CRD commentary

The review question was clear in terms of the interventions and outcomes of interest. The authors did not report explicit inclusion criteria in terms of the study design, but they did report some details of the type of data that eligible studies had to have reported. No explicit inclusion criteria were reported for participants either, other than youths. Only one electronic database was searched and no attempt was made to look for unpublished studies. This means that some important information may have been missed and publication bias cannot be ruled out. No information on the study selection and data extraction processes was given, and the authors do not appear to have assessed the quality of the included studies. This means that the reader cannot assess the potential for errors and reviewer bias.

All the outcome measures reported by the individual studies were pooled into two measures (30-day and regular smoking). There were insufficient details of the individual studies to check whether this approach was appropriate. For the correlation analysis, the data from individual communities, as well as baseline and follow-up data, were treated as separate data points. This means that the same participants would have been included twice for the cohort study. There were insufficient details of the methodology of the included studies to check whether this was the same for any remaining studies. The included studies appear to have varied quite considerably in terms of the interventions and participants, which may limit the meaningfulness of the pooled estimate of the meta-analysis. The authors did not investigate statistical heterogeneity. The authors also stated that their estimated standard errors were probably too small, which would mean that the results would be biased in favour of the intervention. The authors' conclusions appear to follow from the results presented.

Implications of the review for practice and research

Practice: The authors stated that given the limited resources available for tobacco control, as well as the expense of conducting youth access programmes, tobacco control advocates should abandon this strategy and devote the limited resources that are available for tobacco control toward other interventions with proven effectiveness.

Research: The authors did not state any implications for further research.

Funding

National Cancer Institute, grant number CA-61021.

Bibliographic details

Fichtenberg C M, Glantz S A. Youth access interventions do not affect youth smoking. Pediatrics 2002; 109(6): 1088-1092. [PubMed: 12042547]

Original Paper URL

http://pediatrics.aappublications.org/cgi/content/full/109/6/1088

Indexing Status

Subject indexing assigned by NLM

MeSH

Adolescent; Adolescent Behavior /psychology; Child; Commerce /legislation & jurisprudence; Confidence Intervals; Health Policy /legislation & jurisprudence; Humans; Legislation as Topic /standards; Outcome Assessment (Health Care); Prevalence; Program Evaluation /statistics & numerical data; Smoking /epidemiology /legislation & jurisprudence /prevention & control; Social Control, Formal /methods; Tobacco Industry /legislation & jurisprudence; United States /epidemiology

AccessionNumber

12002001384

Database entry date

29/02/2004

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.