Prevalence of and factors affecting otitis media with effusion in children in the region from Balkans to Caspian basin; A multicentric cross-sectional study.

Objective: The aim of our study was to contribute to the literature about the prevalence of OME by conducting a research in a wide geography examining most of the associating factors together with a questionnaire. Additionally, possible effects of altitudes and latitudes, concordance between the otoscopic examination findings and tympanometric and acoustic reflex test results were evaluated in 4-7 years old children in the same season in different countries.

Methods: In the randomly sampled schools from different regions of different cities where people of different scoioecomonic statuses live, 4-7 year-old children were included in the study. The results of the questionnaire covering the potential factors in OME etiology were evaluated together with the results of the otoscopic examination and tympanometry findings, and also the acoustic reflex findings to direct the interpretation in cases of low amplitude - blunted peak tympanograms which can be interpreted as a "Type B" or "Type As". All the results were gathered in the same season.

Results: Ten centers from nine countries participated in the study. A total of 4768 children were evaluated. The frequency of OME diagnosed by otosopic examination was 22.48% (n=1072) and the diagnosis rate when otoscopic examination plus type B tympanometry were taken into account was found as 11.3% (n=539) in general population. Factors increasing the prevalence of OME were found as; mother's educational level (p=0.02), child's age (p=0.006), history of upper respiratory tract infection (p=0.001), smoking father (p=0.01), mother being a housewife or laborer (p=0.01), history of allergy (p=0.001), asthma (p=0.04), or allergy symptoms (p=0.02). No direct relationship was found between altitudes or latitudes and prevalence of OME.

Conclusion: The important affecting factors found after analyzing all of the potential risk factors in the same model are secondhand smoke exposure, low level of mother's education, mother's occupation, positive history of URTI, and age of the child being less than 7. By paying attention to the factors that increase the prevalence of OME, putting particular emphasis on the preventable ones such as smoking, education, and fighting with allergies could decrease the prevalence of this public health issue.