Middle ear effusion and risk factors.

In 373 randomly selected four year old children tympanometric measurements were correlated with the medical history and the results of an otorhinological examination. The purpose of the study was to demonstrate potential risk factors in the evolution of secretory otitis media (SOM). The tympanometric results represent related as well as independent data, making an appropriate choice of statistical model essential. Therefore the tympanometric results were expressed both per child and per ear. Statistical analysis showed that frequent and severe episodes of catarrhalia and hyperplasia of the adenoids must be considered as two separate and predominant risk factors. As a cofactor, previous attacks of acute otitis media were correlated to catarrhalia. Previous adenoidectomy did not positively influence the middle ear pressure. Children who since infancy had been nursed in public day-care centres, showed an increased frequency of Eustachian tube dysfunction and SOM compared with the children cared for in their own homes. Infectious diseases in general, allergy, age, and housing condition did not appear to be influential risk factors.