Exposure to environmental tobacco smoke as a risk factor for recurrent acute otitis media in children under the age of five years.

Exposure to environmental tobacco smoke (ETS) has remained a controversial risk factor for otitis media in children. This study evaluates the association between exposure to ETS and recurrent acute otitis media (RAOM) in 85 cases and 85 age and gender matched controls under the age of 5 years. Cases and controls were obtained from outpatient otolaryngology and ophthalmology clinics, respectively, at the Children's Hospital of Eastern Ontario. Cases were defined as having four or more physician documented AOM episodes in the preceding 12 months and controls were otitis free in the prior 12 months. Exposure status was assessed via parental questionnaire. Controlling for other risk factors (via conditional logistic regression), such as daycare attendance, socioeconomic status, prematurity and family history of otitis media, a significant association between ETS and RAOM was evident (odds ratio = 2.68, 95% CI = 1.27-5.65). When categorized, a significant exposure response relationship between increasing level of exposure to ETS and increased risk of RAOM was evident. The population etiologic fraction indicated that up to 34% of RAOM cases may be accounted for by ETS exposure. We conclude that exposure to ETS is an important and modifiable risk factor for RAOM in children under the age of 5 years.