Background
Smoking remains the leading preventable cause of morbidity and mortality in Europe. Although overall smoking prevalence is declining, socioeconomic inequalities in smoking are widening. Increasing evidence of inequalities in smoking has been reported in Europe, mostly focusing on education. However, few studies have assessed income-related inequalities, and their association with existing tobacco control policies is yet to be investigated.

Objectives
1. Quantify the absolute and relative income-related inequalities in smoking across Europe.
2. Examine the association of tobacco control policies with smoking prevalence and inequalities across Europe.

Methods
We used country-level data from European Health Information Survey (2019) to estimate absolute and relative income-related inequalities in smoking across 31 European countries, using regression-based, rank-dependent measures: the slope index of inequality (SII) and the relative index of inequality (RII). Country scores for overall tobacco control policy and individual policy components were extracted from the Tobacco Control Scale (2019), and their associations with smoking prevalence and inequalities was examined.

Results
Smoking prevalence ranged from 6.4% in Sweden to 28.7% in Bulgaria. The crude difference in prevalence between the highest- and lowest-income groups varied by country, with Italy, Finland, and Portugal showing the smallest gaps, and Netherlands and Hungary the largest. Summary inequality estimates indicated that lowest-income groups consistently had higher smoking prevalence (SII= 5.89, RII= 1.75), with inequalities larger among males (SII= 11.3, RII= 2.03) compared to females (SII= 3.82, RII= 1.64). Country-level comparisons showed the highest inequalities in Netherlands, Hungary, and Bulgaria, and the lowest in Czechia, Italy, and Finland. In most countries, lowest-income groups smoked more than highest-income groups, except in Bulgaria, Romania, and Turkey.

Overall tobacco control policy scores were negatively associated with smoking prevalence (r= -.41, p= .024). Individual policy components generally showed no significant association, except for the “budget” component (r= -.43, p= .024). Neither SII or RII were significantly associated with overall policy scores. However, the “article 5.3” component showed a significant positive association with SII (r= .46, p= .017), and RII was positively associated with “article 5.3” (r= .56, p= .002) and “treatment” (r= .43, p= .015) components.

Conclusions
Our findings indicate that income-related smoking inequalities persist across Europe, disproportionately affecting lower-income groups, with greater disparities among males and notable variation between countries. While stronger tobacco control policies are associated with lower smoking prevalence, they do not appear to be associated with income-related inequalities in smoking.