Authors' objectives: The overall aims of this project were:To synthesise the best available evidence about the differential effects of population tobacco control interventions on groups with different sociodemographic characteristicsTo assess which interventions are likely to be effective in reducing smoking related health inequalities and to identify reasons why other interventions may be ineffective, attempting to answer the questions: What works? What might work? For whom? In what contexts?To extend systematic review methods by integrating existing, related systematic reviews and the primary studies included in those reviews into a new systematic review, taking a broad view of the types of evidence which are available in seeking to answer a policy-relevant question, and To identify where evidence is lacking and to suggest areas where further primary or secondary research is required.The project comprised two parts. Part 1 is a review of existing systematic reviews and Part 2 is a new systematic review of primary studies.

Authors' results and conclusions: Part 1 – A review of existing systematic reviewsWe identified 19 systematic reviews which met the inclusion criteria. Between them, these reviews included the results of 581 unique primary studies. Some population tobacco control interventions were found to be effective at reducing smoking rates in the population as a whole, but only three systematic reviews had explicitly aimed to examine the differential effects of population tobacco control interventions. We found tentative evidence that the effect of increasing the unit price of tobacco may vary between ethnic and socio-economic groups and between men and women.Part 2 – A systematic review of primary studiesWe identified 84 primary studies, which met the inclusion criteria. These studies evaluated the effects of a variety of different types of intervention:Restrictions on smoking in workplaces and public places - overall, there is no strong evidence that restrictions in workplaces and public places are more effective in reducing smoking in more advantaged groups, although attitudes may be more favourably affected among better educated smokers and those in higher occupational grades.Restrictions on smoking in schools, and restrictions on sales of tobacco to minors - we found evidence from single studies that smoking restrictions in schools are more effective in girls and in younger school children, but no evidence with respect to other social gradients, although this is mainly due to an absence of evidence, as few studies reported effectsstratified by socioeconomic status. There is more and better-quality evidence on the differential effects of restrictions on sales to minors: restrictions seem to be more effective ingirls and in younger schoolchildren. One study found restrictions on sales to minors to be more effective in white than non-white groups. We found no evidence with respect to othersocial gradients.Health warnings on tobacco products, and restrictions on tobacco advertising - the small number of studies (and the lack of methodologically robust studies) evaluating theseinterventions make firm conclusions difficult to draw. The effects of health warnings do not appear to be subject to a social gradient, but their effects have not been examined withrespect to income, occupation, or ethnicity, and the evidence with respect to other gradients is not convincing. The effects of advertising bans do not show a gradient by gender or age, but the evidence is not strong, and other social gradients have not been examined in primary studies.The effects of tobacco pricing in adults and adolescents - there is consistent evidence that increasing the price of tobacco is more effective in reducing smoking in lower-income adults. The evidence is also consistent with greater effectiveness among smokers in manual occupations. Higher-educated smokers may also be more responsive to price. The evidence with respect to other variables (gender, ethnicity, age) is less consistent, and can perhaps best be interpreted as “no evidence of differential effects”. Although there are fewer studies of the effects of pricing in children, it appears that boys, non-white children, and perhaps also older children may be more price-sensitive. We found no evidence in relation to differential effects on children by income group.

Authors' recommendations: Implications for policyThese findings carry several implications for policy. One is that, the most compelling evidence of a negative (desirable) social gradient in effectiveness is for the price of tobacco products. Increasing the price of tobacco is the population-level intervention for which there is strongest evidence as a measure for reducing smoking-related inequalities in health.However, effects of increasing tobacco taxation may be undermined by tax evasion or tax avoidance measures such as smuggling and cross-border shopping. The Acheson Inquiryand other commentators have also raised concern about the long-term effect of price rises on disadvantaged households, where smokers are more likely to be nicotine dependent and for whom living in hardship is the primary deterrent to quitting. The policy steer on this point is that extra measures to support cessation among low-income households would be needed, alongside any intensification of pricing policy.Nonetheless, there is certainly more consistent evidence to support increasing the price of tobacco products as a means of reducing social inequalities in smoking than for other more visible interventions, such as health warnings and advertising restrictions, where differential effects appear under-explored. It should also be noted that although interventions such as health warnings and advertising restrictions may not in themselves impact upon inequalities, they may be important as part of a wider tobacco control strategy if they help to elicit public support for other measures.In children and young people, restrictions on sales may be effective in deterring younger smokers, though their effectiveness depends on enforcement. Un-enforced voluntaryagreements with retailers are less effective in reducing sales. Pricing may be less effective among younger children, perhaps because they obtain cigarettes from non-commercialsources. Among this group, restrictions in schools (which affect consumption) and health warnings (which affect attitudes to smoking) may be more productive. Appropriately-enforced restrictions on sales to minors may offer the greatest promise as part of a strategy for tackling inequalities. While combinations of interventions are also likely to be an important part of the policy armoury, the differential effects of such combinations largely remains an area for further research, though they may hold promise for reducing smoking initiation in young people.Aside from identifying interventions which are effective in reducing inequalities, it is also important to identify measures which have the potential to increase inequalities. Here themessage from our review is encouraging, as there was little evidence that the interventions we examined had adverse effects in this regard. One possible exception was restrictions on smoking in the workplace, which may be more effective among higher occupational grades and among staff with higher levels of educational attainment. This suggests that theimplementation of such policies should be accompanied by measures to mitigate adverse effects on inequalities, such as measures to support adherence across all occupationalgrades. The potential for workplace restrictions is therefore dependent on their effective implementation in blue-collar settings. This supports the case for legislating for mandatoryworkplace bans, rather than relying on willing employers to introduce voluntary bans.Implications for researchWe currently know little about the differential effects of the following interventions stratified by income group:Health warnings on tobacco productsRestrictions on tobacco advertisingMulti-component interventionsRestrictions on smoking in schoolsRestrictions on sales of tobacco to minors.With respect to the pricing of tobacco products, a relatively well-researched field, we need to know more about:The effects of price increases on adolescents from lower-income households, and on adolescents and young people in general compared to adults; andThe effects of price increases on lower-income adults, who are more likely to be dependent on nicotine.Other aspects of the social gradient are under-represented in the evidence-base, in particular;The differential effects of most interventions by ethnicity; andThe differential effects between boys and girls in school restrictions, health warnings,advertising restrictions and pricing.Further primary research is indicated in each of these areas. Perhaps most important to note is that most of the existing evidence derives from the US. The greatest research priority should therefore be to develop relevant interventions for other country contexts with a focus on behavioural outcomes. The introduction of new population-level tobacco control policies - such as the restrictions on smoking in public places now introduced in all the countries of the UK and elsewhere – provides such an opportunity.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.york.ac.uk/inst/crd/CRD_Reports/crdreport39.pdf

Year Published: 2008

URL for published report: http://www.york.ac.uk/inst/crd/CRD_Reports/crdreport39.pdf

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: England

Organisation Name: University of York

Contact Address: University of York, York, Y01 5DD, United Kingdom. Tel: +44 1904 321040, Fax: +44 1904 321041,

Contact Name: crd@york.ac.uk

Contact Email: crd@york.ac.uk

Copyright: Centre for Reviews and Dissemination (CRD)