Meta-analysis of the association between secondhand smoke exposure and physician-diagnosed childhood asthma.

Abstract

INTRODUCTION:

Studies suggest an association between secondhand smoke exposure and the development of childhood asthma. Several countries are considering legislation to protect children from exposure.

METHODS:

A systematic review was conducted using MEDLINE, Embase, PubMed, and Web of Knowledge databases and a random effects meta-analysis was undertaken. Heterogeneity was assessed using the I (2) test. Publication and small study biases were examined visually using a funnel plot and tested formally using Egger test. Univariate and multivariate meta-regression analyses were undertaken, including a subgroup analysis of cohort studies to examine the effect of duration of follow-up.

RESULTS:

Twenty relevant studies were identified (14 cross-sectional, 4 cohort, and 2 case-control) and provided 31 estimates of effect size. The pooled odds ratio was 1.32 (95% CI: 1.23, 1.42, p < .001). There was moderate heterogeneity (I (2) = 74.2%, p < .001). On multivariate meta-regression analysis, effect size estimates were significantly higher for case-control studies (p = .042) and those using self-reported exposure to secondhand smoke (p = .050). There was no evidence of significant publication or small study bias (Egger test, p = .121).

CONCLUSIONS:

There is now consistent evidence of a modest association between secondhand smoke and physician-diagnosed childhood asthma. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.

• Authors: Olaitan Tinuoye, Jill P Pell, Daniel F Mackay
• Journal: Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (Nicotine Tob Res) Vol. 15 Issue 9 Pg. 1475-83 (Sep 2013) ISSN: 1469-994X [Electronic] England
• PMID: 23539174 (Publication Type: Journal Article, Meta-Analysis, Review, Systematic Review)

Chemical References

• Tobacco Smoke Pollution

Topics

• Adolescent
• Asthma (chemically induced, epidemiology)
• Child
• Child, Preschool
• Female
• Humans
• Infant
• Male
• Odds Ratio
• Tobacco Smoke Pollution (adverse effects)