Widening socioeconomic inequalities in smoking in Japan, 2001–2016

Hirokazu Tanaka, Johan P. Mackenbach, Yasuki Kobayashi*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

28 Citations (Scopus)
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Background: Japan is one of the world’s largest tobacco epidemic countries but few studies have focused on socioeconomic inequalities. We aimed to examine whether socioeconomic inequalities in smoking have reduced in Japan in recent times. Methods: We analyzed data from the Comprehensive Survey of Living Conditions, a large nationally representative survey conducted every 3 years (n ≈ 700,000 per year) in Japan, during 2001–2016. Age-standardized smoking prevalence was computed based on occupational class and educational level. We calculated smoking prevalence difference (PD) and ratio (PR) of (a) manual workers versus upper non-manual workers and (b) low versus high educational level. The slope index of inequality (SII) and relative index inequality (RII) by educational level were used as inequality measures. Results: Overall smoking prevalence (25–64 years) decreased from 56.0% to 38.4% among men and from 17.0% to 13.0% among women during 2001–2016. The PD between manual and upper non-manual workers (25–64 years) increased from 11.9% (95% confidence interval [CI], 11.0–12.9%) to 14.6% (95% CI, 13.5–15.6%) during 2001–2016. In 2016, smoking prevalence (25–64 years) for low, middle, and highly educated individuals were 57.8%, 43.9%, and 27.8% for men, and 34.7%, 15.9%, and 5.6% for women, respectively. SII and RII by educational level increased among both sexes. Larger socioeconomic differences in smoking prevalence were observed in younger generations, which suggests that socioeconomic inequalities in smoking evolve in a cohort pattern. Conclusions: Socioeconomic inequalities in smoking widened between 2001 and 2016 in Japan, which indicates that health inequalities will continue to exist in near future.

Original languageEnglish
Pages (from-to)369-377
Number of pages9
JournalJournal of Epidemiology
Issue number6
Publication statusPublished - 2021

Bibliographical note

Funding Information:
This study was approved by the Research Ethics Committee of the Graduate School of Medicine, the University of Tokyo (approval no.: 2018112NI). The Ministry of Health, Labour and Welfare approved the secondary use of the data for this study (approval no. 2019-0701-1). Data sharing: No additional data available.

Funding Information:
Funding: HT received the Japan Society for the Promotion of Science (JSPS) Overseas Research Fellowships program grant [201960143] to study at Erasmus MC. The funder had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.

Publisher Copyright:
© 2020 Hirokazu Tanaka et al.


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