Objective: To assess the potential contribution of evidence from existing systematic reviews of effectiveness to answering the question: what works in reducing social inequalities in smoking?
Data source: The Cochrane Library (2002/4).
Study selection: Systematic reviews of the effectiveness of community based tobacco control interventions, and all the primary studies included in one of these reviews.
Data extraction: Reviews and primary studies were assessed for intent to assess the social distribution of intervention effects, information about the social inclusiveness or targeting of interventions, baseline sociodemographic data collected on participants, and estimates of effect size stratified by sociodemographic variables.
Data synthesis: Only one review aimed to examine outcomes stratified by sex, age or socioeconomic status, and these aims were only achieved with respect to sex. Sociodemographic data about participants were frequently collected in primary studies, but not used to compare intervention effects between social groups.
Conclusions: There may be scope for using existing research more effectively to contribute to evidence based policy to reduce social inequalities in smoking-by explicitly seeking stratified outcome data in new systematic reviews, by re-analysing original datasets, and/or by meta-analysis of individual participant data.