Parental smoking and the risk of middle ear disease in children: a systematic review and meta-analysis.

OBJECTIVE A systematic review and meta-analysis of studies of the association between secondhand tobacco smoke (SHTS) and middle ear disease (MED) in children. DATA SOURCES MEDLINE, EMBASE, and CAB abstracts (through December 2010) and reference lists. STUDY SELECTION Sixty-one epidemiological studies of children assessing the effect of SHTS on outcomes of MED. Articles were reviewed, and the data were extracted and synthesized by 2 researchers. MAIN OUTCOME EXPOSURES: Children's SHTS exposure. MAIN OUTCOME MEASURES Middle ear disease in children. RESULTS Living with a smoker was associated with an increased risk of MED in children by an odds ratio (OR) of 1.62 (95% CI, 1.33-1.97) for maternal postnatal smoking and by 1.37 (95% CI, 1.25-1.50) for any household member smoking. Prenatal maternal smoking (OR, 1.11; 95% CI, 0.93-1.31) and paternal smoking (OR, 1.24; 95% CI, 0.98-1.57) were associated with a nonsignificant increase in the risk of MED. The strongest effect was on the risk of surgery for MED, where maternal postnatal smoking increased the risk by an OR of 1.86 (95% CI, 1.31-2.63) and paternal smoking by 1.83 (95% CI, 1.61-2.07). CONCLUSIONS Exposure to SHTS, particularly to smoking by the mother, significantly increases the risk of MED in childhood; this risk is particularly strong for MED requiring surgery. We have shown that per year 130 200 of child MED episodes in the United Kingdom and 292 950 of child frequent ear infections in the United States are directly attributable to SHTS exposure in the home.