Complementary diagnostic value of tympanometry and tubomanometry in Eustachian tube dysfunction: a retrospective...

Clinical diagnosis of Eustachian tube dysfunction (ETD) lacks an objective gold standard. Tympanometry (assessed by Type Y tympanogram incidence) and tubomanometry (TMM) are widely used, but their comparative diagnostic performance and combined value remain controversial.

To retrospectively evaluate and compare the diagnostic accuracy and agreement of tympanometry and TMM for ETD, using clinical comprehensive diagnosis as the reference, and to explore the clinical utility of serial and parallel diagnostic strategies.

This single-center retrospective study consecutively enrolled 165 patients with ear symptoms who underwent both tests (January 2022-January 2025). Clinical comprehensive diagnosis (blinded to test results) served as the gold standard. Sensitivity, specificity, predictive values, accuracy, area under the ROC curve (AUC), and Cohen's Kappa were calculated. Serial (both tests positive) and parallel (either test positive) strategies were evaluated.

ETD was diagnosed in 75/165 patients (45.5%). The AUC for TMM was 0.875 (95% CI: 0.825-0.925), higher than that for tympanometry (0.836, 95% CI: 0.786-0.886), but the difference was not statistically significant (P = 0.375). Tympanometry showed very high sensitivity (0.987) and NPV (0.985) but low specificity (0.711); TMM had higher specificity (0.778) and PPV (0.765). Agreement between the two methods was moderate (Kappa = 0.475, overall agreement 73.9%). Among combined strategies, the serial approach yielded the highest specificity (0.922) and accuracy (0.891), while the parallel approach demonstrated high sensitivity suitable for screening but with low specificity (0.567).

Tympanometry and TMM exhibit complementary diagnostic characteristics: tympanometry is an excellent screening tool for ruling out ETD, whereas TMM is more reliable for confirmation. The moderate agreement suggests they capture different pathophysiological dimensions of ETD. The serial strategy optimizes diagnostic specificity and accuracy, supporting its use when confirmation is required.