Socioeconomic inequality in cigarette smoking among Iranian households

Socioeconomic conditions play a pivotal role in influencing smoking patterns. The aim of this study was to examine socioeconomic inequalities in cigarette smoking among households (CSH) and explain the factors contributing to these inequalities across Iranian households at a national level. This cross-sectional study was conducted using a sample of 37,759 households from the Iran Household Income and Expenditure Survey of 2021. Univariate analysis and logistic regression were used to assess factors related to smoking. Moreover, the Concentration Index (CI) was used to assess socio-economic inequality in CSH. All analyses accounted for sampling weights and employed cluster-robust standard errors. Data were analyzed using Stata 17. The prevalence rates of CSH in Iran were 8.5% for domestically produced cigarettes, 5.9% for imported cigarettes, and 14.5% overall. The CI for overall cigarette smoking was not significant (− 0.011; 95%CI: −0.033, 0.010), yet it became negative for domestic cigarettes (− 0.061; 95%CI: -0.090, -0.033) and positive for imported cigarettes (0.048; 95%CI: 0.011, 0.084), indicating pro-poor and pro-rich inequalities, respectively. Male-headed, unemployed-headed, poorer/middle quintiles, and households with more literate/employed/income-earning members had higher smoking odds, whereas higher education of the head was protective ( P < 0.05). Overall cigarette smoking is equally distributed among Iranian households, but domestic cigarettes show pro-poor inequality and imported cigarettes show pro-rich inequality. Smoking is more common in male-headed, unemployed-headed, and second-quintile households, and less common where the head is more educated. Prevention should target these high-risk groups.