Health effects of passive smoking. 4. Parental smoking, middle ear disease and adenotonsillectomy in children.

BACKGROUND A systematic quantitative review was conducted of evidence relating parental smoking to acute otitis media, recurrent otitis media, middle ear effusion, and adenoidectomy and/or tonsillectomy. METHODS Forty five relevant publications were identified after consideration of 692 articles selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified 13 studies of acute otitis media, nine of recurrent otitis media, five of middle ear effusion, nine of glue ear surgery, and four of adenotonsillectomy. A quantitative meta-analysis was possible for all outcomes except acute otitis media, using random effects modelling where appropriate to pool odds ratios from each study. RESULTS Evidence for middle ear disease is remarkably consistent, with pooled odds ratios if either parent smoked of 1.48 (95% CI 1.08 to 2.04) for recurrent otitis media, 1.38 (1.23 to 1.55) for middle ear effusion, and 1.21 (0.95 to 1.53) for outpatient or inpatient referral for glue ear. Odds ratios for acute otitis media are in the range 1.0 to 1.6. No single study simultaneously addresses selection bias, information bias and confounding, but where these have been investigated or excluded in the design or analysis, the associations with parental smoking persist virtually unchanged. Large French and British studies are inconsistent with regard to the association of parental smoking and tonsillectomy. CONCLUSIONS There is likely to be a causal relationship between parental smoking and both acute and chronic middle ear disease in children.