title: Predicting the development and outcome of otitis media by tympanometry.
abstract: OBJECTIVE
  Identification of children with high risk of development or prolongation of otitis media would be highly useful in clinical practice. In this study, tympanometry was assessed for its capability in predicting development and resolution of acute otitis media (AOM).
  
  
  METHODS
  Visits of 329 children followed in the Finnish Otitis Media Cohort Study from 2 to 24 months of age were evaluated for this report. Tympanometry was routinely performed on all children during their visits to a special study clinic. Adjacent consecutive visits were used for analysis of development and resolution of middle ear fluid (MEF) between the visits. Descriptive analysis utilized all data obtained during the longitudinal follow-up; confirmatory statistical analysis was performed on data of one randomly selected visit per subject to ensure independence of observations. Presence of MEF at the second visit was used as the outcome.
  
  
  RESULTS
  Negative tympanometric peak pressure (<-100 daPa) was found to predict the development of otitis media when observed during respiratory infection with no concomitant ear disease. Otitis media developed within 20 days to 40% of children with negative pressure compared with 20% of children without negative pressure. The observed association was confirmed statistically (odds ratio 4.8, 95% confidence interval 2.4-9.6). Poor outcome of AOM at the subsequent follow-up visit 3-5 weeks later was found in 9% of ears with negative pressure tympanogram compared with 24% with initial type B or normal pressure tympanogram during AOM. However, we could not confirm the finding in statistical analysis (odds ratio 0.6, 95% confidence interval 0.2-2.0).
  
  
  CONCLUSIONS
  Profound negative tympanometric peak pressure is a significant marker of increased risk for development of otitis media. Children with negative pressure have to be thoroughly followed for subsequent progress of the respiratory disease and development of otitis media. For the prediction of resolution of AOM, the findings remained inconclusive.
authors.affiliation: National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland. aapalmu@tays.fi
authors.forename: Arto
authors.initials: A
authors.lastname: Palmu
authors.forename: Heikki
authors.initials: H
authors.lastname: Puhakka
authors.forename: Tapani
authors.initials: T
authors.lastname: Rahko
authors.forename: Aino
authors.initials: A
authors.lastname: Takala
authors.forename: Terhi
authors.initials: T
authors.lastname: Kilpi
mesh_terms: D000158:Acoustic Impedance Tests; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D010033:Otitis Media / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011312:Pressure; D012307:Risk Factors; D013997:Time Factors