The repeatability of tests of eustachian tube function in healthy ears

Many objective tests of eustachian tube (ET) function have been devised for clinical and research use but they have not been directly compared or characterized. As a first step to identifying tests to incorporate into an outcome set for ET dysfunction, we assessed repeatability of a panel of eight of these tests in healthy ears.

Comparison of eight tests of ET function.

The following tests were investigated in combination with Valsalva, Toynbee, swallow, or sniff maneuvers: 1) patient-reported ET opening, 2) observed tympanic membrane movement, 3) continuous impedance, 4) canal manometry, 5) sonotubometry, 6) nine-step test, 7) tubomanometry, and 8) tympanometry at rest. Forty-two healthy volunteers were recruited. Each test was performed in 20 different ears and repeated immediately three times in each cycle, with four cycles performed at 20-minute intervals. Repeatability of detected ET opening was compared using the intraclass correlation coefficient (ICC).

Mean ET opening rate with each test ranged from 30% to 95%. Variation in detection of ET opening was less when tests were repeated immediately (ICC = 0.61) when compared to between cycles (ICC = 0.49), suggesting there may be significant changes in ET function in the short term. Tubomanometry was the only test to combine a detected ET opening rate of >85% and substantial agreement of results (ICC >0.61) between test cycles.

Tubomanometry was the most reliable test at detecting ET opening. When tests of ET function are used in clinical practice, they should be performed more than once to gain a more reliable result.

3b. Laryngoscope, 127:2619-2626, 2017.