The natural course of otitis media with effusion in preschool children.

In order to gain an insight into the natural course of otitis media with effusion (OME), a prospective study was carried out on 1328 children out of a cohort of 1439 preschool children. These children were seen in follow-up for their OME every 3 months, at which times tympanometry was performed. The results show a fairly constant rate of improvement of about 50% every 3 months. The cumulative rate of recurrence of OME was about 50% in the study period. Two-thirds of all OME with flat tympanograms had a duration of less than 3 months. Some factors could be identified as having an effect on the natural history of OME. The season and patients' age and sex were found to be associated with the duration and the recovery rate. Risk factors for recurrences were the same as those already reported in the literature.