VALIDATION OF A PORTABLE TYMPANOMETER FOR USE IN PRIMARY-CARE

Objective - to determine the accuracy of a handheld, portable tympanom eter, the microtymp, in comparison with a reference instrument, the AR 85 tympanometer, and with the gold standard: presence or absence of m iddle-ear fluid. Design - comparison of results from the microtymp wit h results from the reference tympanometer, the AR 85 and the gold stan dard. Setting - University Children's Hospital, Utrecht and the Genera l Hospital, Overvecht, Utrecht. Subjects - 142 children (284 ears) age d between 6 months and 12 years, who were referred by their General Pr actitioner or Ear, Nose and Throat surgeon for myringotomy and/or tymp anostomy tube insertion. Main outcome measures - tympanometry with the AR 85 and presence or absence of middle-ear fluid. Results - In 243 e ars, of the included 284 ears, the test results of the microtymp were compared with those of the reference instrument, the AR 85 tympanomete r. Sensitivity 0.96 (95% C.I.: 0.93, 0.99), Specificity 0.81 (95% C.I. : 0.71, 0.91). In 233 ears, of the included 284 ears, the test results of the microtymp were compared with the gold standard. Sensitivity 0. 94 (95% C.I.: 0.90, 0.98), specificity 0.48 (95% C.I.: 0.37, 0.59). Co nclusion - The microtymp is a valid instrument for diagnosing middle-e ar effusions. The results of the microtymp are highly comparable with traditional tympanometers: high sensitivity and much lower specificity . Use in primary care can increase diagnostic accuracy of otitis media with effusion (OME) and makes follow-up possible. This will help to d iscriminate between those OME cases who need further treatment and tho se who will resolve spontaneously.