Impact of population tobacco control interventions on socioeconomic inequalities in smoking: a systematic review and appraisal of future research directions.

Researchers need to adopt more sophisticated, multidisciplinary approaches in evaluating the equity impact of tobacco control measures-developing robust measures of equity effect and using frameworks that take account of context, existing systems/processes and the likely mechanisms of action. Socioeconomic differences in intervention impact within low-income and middle-income countries require evaluation.