Window of Susceptibility to Acute Otitis Media Infection.

Background: Contemporary, quantitative data are needed to inform recommendations and decision-making regarding referral and surgeon endorsement of tympanostomy tube placement in young children with recurrent acute otitis media (AOM).

Methods: A prospective, observational cohort study of 286 children in a primary care pediatric practice setting, who had at least 1 AOM (range 1-8). Children were followed longitudinally from 6 to 36 months old. AOMs were microbiologically confirmed by tympanocentesis for diagnostic accuracy. A window of susceptibility (WOS) was defined as AOMs closely spaced in time with no gap in occurrence >6 months. For prediction of total number of AOMs, we used a quasi-poisson generalized linear model.

Results: Eighty percent of AOMs occurred during child age 6 to 21 months old. Seventy two percent of WOS intervals were <5 months and 97% were <10 months. Clinically applicable models were developed to predict which children would benefit most from tympanostomy tubes. Significant predictors were child age at the first AOM (P < .001) and daycare attendance (P = .03). The age of a child when 2, 3, or 4 AOMs had occurred allowed prediction of the number of additional AOMs that might occur. After insertion of tympanostomy tubes, 16 (52%) of 31 children had no additional AOMs.

Conclusions: Recurrent AOM occurs in a narrow WOS and number of AOMs can be predicted at time of AOM based on child age and daycare attendance. Insertion of tympanostomy tubes likely occurs in many children after the WOS to recurrent AOM has passed or only 1 more AOM may be prevented at most.