Equity impact of European individual-level smoking cessation interventions to reduce smoking in adults: a systematic review

Background: Smoking is the leading cause of health inequalities in Europe. Adults from lower socioeconomic status (SES) groups are more likely to smoke and less likely to quit than adults from higher SES groups. Smoking cessation support is an important element of tobacco control; however, the equity impact of individual-level cessation support is uncertain. Methods: Systematic review of individual-level smoking cessation interventions delivered in European countries, reporting a smoking cessation outcome (quit) in adults of lower compared with higher SES. Equity impact was assessed as positive (reduced inequality), neutral (no difference by SES), negative (increased inequality) or unclear. Results: Twenty-nine studies were included using different types of support: behavioural and pharmacological (17); behavioural only (11), including specialist (5), brief advice (1), mass media (2), text-based (1) and Internet-based (2); and pharmacological only (1). The distribution of equity effects on quitting was 10 neutral, 18 negative and 1 unclear. Two national studies of UK National Health Service (NHS) stop-smoking services showed overall positive equity impact on smoking prevalence. The evidence suggests that UK NHS services that target low-SES smokers achieve a relatively higher service uptake among low-SES smokers, which can compensate for their lower quit rates. Conclusions: Untargeted smoking cessation interventions in Europe may have contributed to reducing adult smoking but are, on balance, likely to have increased inequalities in smoking. However, UK NHS stop-smoking services appear to reduce inequalities in smoking through increased relative reach through targeting services to low-SES smokers. More research is needed to strengthen the evidence-base for reducing smoking inequalities.