Trends in Socio-economic Inequality in Smoking Among Middle-aged and Older Adults in China: Evidence From the 2011 and 2018 China Health and Retirement Longitudinal Study.

Introduction: Socio-economic inequalities in smoking and related health problems are a public health concern worldwide. To support the development of effective tobacco control policies, this study examines trends in smoking rates according to socio-economic status (SES) in China.

Aims And Methods: We analyzed data from repeated cross-sectional China Health and Retirement Longitudinal Study (CHARLS) on adults aged ≥45 years for the years 2011 and 2018, which involved 16 471 participants in 2011 and 19 367 in 2018. We then estimated the SES of individuals based on four types of wealth-related variables, namely, education, occupation, household characteristics, and durable consumer goods. Principal-component analysis was conducted to measure SES, and the Erreygers normalised concentration index (ECI) was used to calculate socio-economic inequality in current smoking by gender, age, and region.

Results: The overall ECI (95% confidence interval) for women was -0.042 (-0.054 to -0.031) and -0.038 (-0.047 to -0.029) for 2011 and 2018, respectively. The ECI (95% confidence interval) for men was -0.077 (-0.101 to -0.050) and -0.019 (-0.042 to 0.005) for 2011 and 2018, respectively. The inequality in smoking by SES for adults aged < 60 years in the Northeast region increased during 2011-2018, from -0.069 (-0.144 to 0.006) to -0.119 (-0.199 to -0.038) for women and from 0.009 (-0.115 to 0.132) to -0.164 (-0.296 to -0.032) for men.

Conclusions: smoking inequality by socio-economic among adults aged ≥45 years declined in recent years in China. However, smoking inequality by SES increased in other population groups.

Implications: Our research indicated that socio-economic inequality of current smoking among residents aged 45 years and older declined in 2018 when compared with 2011 numbers, particularly for men aged ≥ 60 years. Women in the Northeast region displayed more significant smoking inequality by SES than women in other regions did. During the study period, there was an increase in inequality in smoking by SES for adults aged < 60 years in the Northeast region. Thus, tobacco control policies and interventions should be targeted at high-risk subpopulations with lower SES, particularly in Northeast China.