Meta-analysis of the association between secondhand smoke exposure and stroke

Oono, I. P., Mackay, D. F. and Pell, J. P. (2011) Meta-analysis of the association between secondhand smoke exposure and stroke. Journal of Public Health, (doi: 10.1093/pubmed/fdr025)

Abstract

Background Active smoking is a recognized risk factor for stroke. We determined the evidence for an association with secondhand smoke exposure. Methods A systematic review was undertaken according to PRISMA guidelines. Random effects meta-analysis provided a pooled estimate of risk, and heterogeneity quantified using I2 values. Potential publication and study bias were assessed using a funnel plot and Egger's test. Meta-regression analyses were used to investigate sources of heterogeneity. Results The 20 eligible studies provided 35 estimates of risk derived from 885 307 participants, of whom 5894 (0.7%) suffered a stroke. The pooled estimate of risk was 1.25 (95% CI: 1.12–1.38) with no evidence of significant publication or small-study bias. There was moderate heterogeneity (I2 = 54.2%, P < 0.001) but no study characteristics were statistically significant in the meta-regression analysis. There was a non-linear dose relationship. The relative risk increased from 1.16 (95% CI: 1.06–1.27) for exposure to 5 cigarettes/day to 1.56 (95% CI: 1.25–1.96) for exposure to 40 cigarettes/day. Conclusions There is evidence of a strong, consistent and dose-dependent association between exposure to secondhand smoke and risk of stroke, suggestive of a causal relationship, with disproportionately high risk at low levels of exposure suggesting no safe lower limit of exposure.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mackay, Professor Daniel and Pell, Professor Jill
• Authors: Oono, I. P., Mackay, D. F., and Pell, J. P.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Public Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Centre for Population and Health Sciences
• Journal Name: Journal of Public Health
• Publisher: Oxford University Press
• ISSN: 1741-3850
• Published Online: 21 March 2011