Socioeconomic differences in secondhand smoke exposure among children in Scotland after introduction of the smoke-free legislation
- Patricia C Akhtar1,
- Sally J Haw2,
- Kate A Levin1,
- Dorothy B Currie1,
- Rachel Zachary3,
- Candace E Currie1
- 1 University of Edinburgh, United Kingdom;
- 2 NHS Health Scotland, United Kingdom;
- 3 Edinburgh Napier University, United Kingdom
- * Corresponding author; email: patricia.akhtar{at}ed.ac.uk
- Received 4 November 2008
- Accepted 9 June 2009
- Published Online First 13 August 2009
Abstract
Objective: To examine the impact of the Scottish smoke-free legislation on social inequalities in secondhand smoke (SHS) exposure among primary schoolchildren.
Design: Comparison of nationally representative, cross-sectional, class based surveys carried out in the same schools before and after legislation.
Participants 2532 primary schoolchildren (primary 7; aged around 11 years) surveyed in January 2006 (before legislation) and 2389 in January 2007 (after legislation).
Outcome measures: Salivary cotinine concentrations, self-reported family socioeconomic classification (family SEC) and family affluence scale (FAS).
Results: After adjusting for number of smoking parents mean cotinine concentration varied significantly across both family SEC and FAS groups, and increased significantly stepwise from high to low family SEC/FAS. Mean cotinine fell in all family SEC/FAS groups after legislation. The relative drop in mean cotinine was equal across all family SEC/FAS groups. Adding an interaction term between survey year and family SEC/FAS to the model, showed an increase in inequalities over time, but was only significant at the 93% level using FAS and 73% using family SEC.
Conclusion: Inequalities in SHS exposure exist among 11 year old children in Scotland. Smoke-free legislation has reduced exposure to SHS among all children. Although the greatest absolute reduction in cotinine is observed in the lowest SEC/FAS group, cotinine levels remain highest for this group and there is a suggestion of possible increases in inequalities which may warrant longer-term monitoring.
