Accuracy of an automatic impedance apparatus in a population with secretory otitis media: principles in the evaluation of tympanometrical findings.
BACKGROUND
The primary demand for a screening procedure for secretory otitis media (SOM) is to identify an objective test with sufficient sensitivity and specificity to meet the needs of the screening program. This study was designed to estimate the value of a portable automatic impedance apparatus to meet these needs.


METHODS
Two hundred twenty children with unilateral or bilateral SOM were evaluated in a double-blind, cross-sectional study. All have fulfilled two of the following three criteria for surgical intervention: (1) SOM by physical examination, (2) greater than 20 dB hearing impairment, and/or (3) adenoid symptoms. All ears were evaluated using tympanometry, following which myringotomy was performed.


RESULTS
Otomicroscopy showed fluid behind the tympanic membrane in 393 ears. All underwent myringotomy. Thirteen percent (51 ears) were empty. Of the otomicroscopic findings consistent with SOM, 82% had B curves, 6% had C2 curves, 8% had C1 curves, and 4% had A curves. Both C2 and B curves were considered abnormal. Sensitivity of the apparatus is 94.4% and of the specificity is 52.9%. There was no statistical correlation between tympanometrical findings and fluid viscosity.


RESULTS
A test intended for screening has to be simple, easy, and quick to perform. Furthermore, the test should have high sensitivity. The automatic impedance apparatus is able to meet these demands; however, the individual results have to be confirmed by another method, eg, otomicroscopy, pure-tone audiometry, and/or manual tympanometry.
Ovesen
T
T
Ear Nose and Throat Department, Aarhus University Hospital, Denmark.
Paaske
P B
PB
Elbrönd
O
O
D000158:Acoustic Impedance Tests / Q000295:instrumentation* / Q000379:methods; D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D007761:Labyrinthine Fluids / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008403:Mass Screening; D008876:Middle Ear Ventilation; D010034:Otitis Media with Effusion / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity