Seasonal Variation in Preschool Hearing Screening Outcomes

OBJECTIVES: To determine whether pass and referral rates for pure-tone audiometry (PTA) and otoacoustic emissions (OAE) demonstrate seasonal variation in preschool-aged children, and to explore whether these patterns may be associated with middle ear pathology related to upper respiratory tract infections. DESIGN: We conducted a secondary analysis of a randomized controlled trial comparing single-stage OAE versus 2-stage PTA plus OAE screening in preschool children from 2023 to 2026. A total of 7416 children completed at least 1 screening modality in at least 1 ear. Children who failed screening underwent tympanometry to characterize middle ear status. Multivariable logistic regression models were used to assess the association between screening season and failure rates, adjusting for age, home language, and teacher-reported concerns. In addition, a time series model using national upper respiratory infection emergency department visit data was developed to estimate seasonal variation in middle ear effusion rates. RESULTS: Failure rates were higher for OAE than PTA and demonstrated clear seasonal patterns. OAE failure rates peaked in spring (17.9%) and winter (15.2%) and were lowest in summer (8.5%) and fall (10.3%). PTA showed a similar pattern, with the highest failure rates in spring (8.3%), followed by winter (5.5%), and the lowest in summer (3.1%) and fall (3.6%). In adjusted analyses, the odds of failure for both OAE and PTA were significantly lower in summer and fall compared with winter (PTA: summer odds ratio (OR) = 0.54, p = 0.004; fall OR = 0.60, p = 0.01; OAE: summer OR = 0.47, p < 0.001; fall OR = 0.57, p < 0.001). For PTA, the odds of failure were significantly higher in spring compared with winter (OR = 1.50, p = 0.004), whereas no significant difference between spring and winter was observed for OAE (OR = 1.15, p = 0.09). Pairwise comparisons demonstrated significantly higher odds of failure in spring compared with summer and fall for both modalities (all p < 0.001). Tympanometry in failed ears most commonly demonstrated type B patterns across all seasons, consistent with middle ear pathology. Modeled effusion rates closely paralleled observed screening failure rates, with shared seasonal peaks and summer nadirs. CONCLUSIONS: Hearing screening failure rates in preschool children vary by season, with higher failure rates observed in winter and spring. These patterns may be driven in part by seasonal variation in middle ear pathology associated with upper respiratory infections. The timing of screening may influence referral rates and should be considered when designing preschool hearing screening programs.