Abstract
HYPOTHESIS: Eustachian tube function is stable over time in children with ventilation tubes for chronic otitis media with effusion. BACKGROUND: Clinical studies report that Eustachian tube function tests in patients with a persistent tympanic membrane perforation predict the success of myringoplasty, and those in patients with ventilation tubes for chronic otitis media predict disease recurrence after the tubes become nonfunctional. In those studies, Eustachian tube function was usually tested only once, which presumes a semi-stable basal level of function for greatest diagnostic and prognostic usefulness. We investigated the stability of repeated measurements of Eustachian tube function using the forced response test. METHODS: Thirty-nine children aged 36 to 83 months with bilateral ventilation tubes for chronic otitis media with effusion were evaluated using the forced response test 3 times at 3- to 4-month intervals. The variability across test sessions in the Eustachian tube opening pressure, closing pressure, and dilatory efficiency was estimated using regression/correlation analyses. RESULTS: For all test parameters, the between-session and between-ear correlation coefficients were significant, but the shared variance in the parameters among test sessions and between ears at the same test session was relatively low. The average slope for each parameter as a function of the time with a ventilation tube was zero. CONCLUSION: The low between-test shared variance for the test parameters raises questions as to whether a single forced response test captures sufficient information to accurately diagnose the cause of any dysfunction or to predict with high specificity and sensitivity future disease experience or surgical results.