title: Meta-analysis of the association between second-hand smoke exposure and ischaemic heart diseases, COPD and stroke.
abstract: BACKGROUND
  Second-hand smoke (SHS) is the most important contaminant of indoor air in first world countries. The risks associated with SHS exposure are highly relevant, because many people are regularly, and usually involuntarily, exposed to SHS. This study aims to quantify the effects of SHS exposure. Therefore, its impact on ischaemic heart diseases (IHD), chronic obstructive pulmonary diseases (COPD) and stroke will be considered.
  
  
  METHODS
  A systematic literature review was conducted to identify articles dealing with the association between SHS and the three outcomes IHD, COPD and stroke. Overall, 24 articles were included in a meta-analysis using a random effects model. Effect sizes stratified for sex and for both sexes combined were calculated.
  
  
  RESULTS
  The synthesis of primary studies revealed significant effect sizes for the association between SHS exposure and all three outcomes. The highest RR for both sexes combined was found for COPD (RR = 1.66, 95 % CI: 1.38-2.00). The RR for both sexes combined was 1.35 (95 % CI: 1.22-1.50) for stroke and 1.27 (95 % CI: 1.10-1.48) for IHD. The risks were higher in women than in men for all three outcomes.
  
  
  CONCLUSIONS
  This is the first study to calculate effect sizes for the association between SHS exposure and the disease outcomes IHD, COPD, and stroke at once. Overall, the effect sizes are comparable with previous findings in meta-analyses and therefore assumed to be reliable. The results indicate the high relevance of public health campaigns and legislation to protect non-smokers from the adverse health effects attributable to SHS exposure.
authors.affiliation: Department of Public Health Medicine, School of Public Health, University of Bielefeld, P.O. Box 100 131, 33501, Bielefeld, Germany. f.fischer@uni-bielefeld.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Fischer
authors.affiliation: Department of Public Health Medicine, School of Public Health, University of Bielefeld, P.O. Box 100 131, 33501, Bielefeld, Germany. alexander.kraemer@uni-bielefeld.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kraemer
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000209:etiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology*; D020521:Stroke / Q000209:etiology*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution