Socioeconomic inequality in smoking and its determinants in the Islamic Republic of Iran

Background: The role of socioeconomic inequality and related factors has not been well reported in tobacco consumption. Aims: To investigate the socioeconomic inequality in smoking and its associated factors in the Islamic Republic of Iran. Methods: Data were collected from surveillance for noncommunicable diseases in 2005, which included 89 404 people aged 15-65 years. Economic status was defined by principal component analysis on variables related to socioeconomic status. Concentration index and slope index of inequality were used to determine the inequality value. The gap between the high and low economic status groups was decomposed using the Oaxaca-Blinder decomposition method for explained and unexplained components. Results: The total prevalence of smoking was 17.0%; 28.0% in males, and 5.8% in females, 15.8% in urban and 19.1% in rural areas. The concentration index was -0.032 in the whole of country; -0.098, in males, -0.246 in females, 0.014 in urban and -0.059 in rural areas and varied in different provinces of country. The smoking rate was 18.0% for the first quintile and 13.5% for the fifth quintile, a gap of 4.5%. The major part of this gap was related to differences in education level, sex, marital status and age in economic groups. Conclusion: There was a pro-rich socioeconomic inequality in smoking, especially in females and in the southern provinces. Increase in education level and empowering females of low socioeconomic status are sound interventions for alleviating inequality and for tobacco control.