Outcome Measures for Baro-Challenge-Induced Eustachian Tube Dysfunction: A Systematic Review.

Abstract

Baro-challenge-induced Eustachian tube dysfunction (baro-induced ETD) is characterized by failure of the Eustachian tube (ET) to open adequately to permit middle-ear pressure regulation during ambient pressure changes. There are no well-characterized tests for identifying the condition, which makes both patient diagnosis and research into treatment efficacy challenging. This systematic review evaluates ET function tests as potential outcome measures for baro-induced ETD. MEDLINE and CENTRAL were searched (database inception to March 2017) and reference lists reviewed for all relevant English Language articles. Tests in included studies were required to measure ET function in patients reporting baro-induced ear symptoms or barotrauma. Data were extracted in a standardized manner, and studies assessed according to Standards for Reporting of Diagnostic Accuracy Studies (STARD) criteria. The primary outcome of interest was the accuracy of ET function tests. Heterogeneity of subject demographics, ET function test methodology, and reference standards only permitted narrative systematic review. Sixteen studies involving seven different types of ET function tests were identified. The nine-step test was the most commonly used outcome measure, with overall test sensitivity and specificity ranges of 37 to 100% and 57 to 100%, respectively. Tympanometry test sensitivity was consistently poor (0-50%) while specificity was higher (52-97%). Published accuracy data for other ET function tests and test combinations were limited. Currently, no single test can be recommended for use in clinical practice. A combination of the nine-step test with other objective tests or patient-reported measures appears most promising as a core set of outcome measures for baro-induced ETD.