Effect of tobacco smoking on survival of men and women by social position: a 28 year cohort studyBMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b480 (Published 18 February 2009) Cite this as: BMJ 2009;338:b480
- Laurence Gruer, director of public health science1,
- Carole L Hart, research fellow2,
- David S Gordon, head of public health observatory division1,
- Graham C M Watt, professor of general practice3
- 1NHS Health Scotland, Elphinstone House, Glasgow G2 2AF
- 2Public Health and Health Policy, Division of Community-based Sciences, University of Glasgow, Glasgow G12 8RZ
- 3General Practice and Primary Care, Division of Community-based Sciences, University of Glasgow, Glasgow G12 9LX
- Correspondence to: L Gruer
- Accepted 16 December 2008
Objective To assess the impact of tobacco smoking on the survival of men and women in different social positions.
Design A cohort observational study.
Setting Renfrew and Paisley, two towns in west central Scotland.
Participants 8353 women and 7049 men aged 45-64 years recruited in 1972-6 (almost 80% of the population in this age group). The cohort was divided into 24 groups by sex (male, female), smoking status (current, former, or never smokers), and social class (classes I + II, III non-manual, III manual, and IV + V) or deprivation category of place of residence.
Main outcome measure Relative mortality (adjusted for age and other risk factors) in the different groups; Kaplan-Meier survival curves and survival rates at 28 years.
Results Of those with complete data, 4387/7988 women and 4891/6967 men died over the 28 years. Compared with women in social classes I + II who had never smoked (the group with lowest mortality), the adjusted relative mortality of smoking groups ranged from 1.7 (95% confidence interval 1.3 to 2.3) to 4.2 (3.3 to 5.5). Former smokers’ mortalities were closer to those of never smokers than those of smokers. By social class (highest first), age adjusted survival rates after 28 years were 65%, 57%, 53%, and 56% for female never smokers; 41%, 42%, 33%, and 35% for female current smokers; 53%, 47%, 38%, and 36% for male never smokers; and 24%, 24%, 19%, and 18% for male current smokers. Analysis by deprivation category gave similar results.
Conclusions Among both women and men, never smokers had much better survival rates than smokers in all social positions. Smoking itself was a greater source of health inequality than social position and nullified women’s survival advantage over men. This suggests the scope for reducing health inequalities related to social position in this and similar populations is limited unless many smokers in lower social positions stop smoking.
Victor Hawthorne conducted the original Midspan studies, and Pauline MacKinnon is the Midspan administrator.
Contributors: LG had the original idea for the paper and the visual display of the data. CLH conducted the statistical analyses. All the authors participated in designing the analyses, interpreting the results, and writing the manuscript. LG is the guarantor for the study.
Funding: LG and DSG are employees of NHS Health Scotland. CLH and GCMW are employees of the University of Glasgow. The analyses conducted by CLH were funded by NHS Health Scotland. The original Renfrew Paisley study was funded by the King Edward Memorial Fund and the Scottish Home and Health Department.
Independence of authors: The views expressed in this paper are those of the authors alone.
Competing interests: None declared.
Ethical approval: Not required.
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