Phenotypic Subtypes of Obstructive Eustachian Tube Dysfunction as Defined by Cluster Analysis

Eustachian tube dysfunction (ETD) is traditionally classified as either patulous or obstructive. Recent evidence suggests that obstructive ETD may comprise a broad array of clinical presentations. This study aimed to define subtypes of obstructive ETD according to common clinical features.

This cross-sectional study included adults diagnosed with ETD at a single academic medical center between October 2014 and June 2022. Clinical data was recorded, including patient-reported ETDQ-7 score, nasal endoscopy findings, tympanometry findings, medical comorbidities, timing of symptoms, symptom laterality and duration of ear fullness. Principle component analysis (PCA) was used to distinguish the most important clinical features and hierarchical cluster analysis was used to delineate symptom cluster groups.

Among 490 obstructive ETD patients, seven clinical characteristics were found to be the most important: duration, severity, laterality, constancy, sinusitis symptoms, history of pressure equalization tube, and comorbid reflux disease. Five phenotypic clusters were described by the clinical data, which were predictive of relative risk of comorbidity of sinusitis and GERD, as well as abnormality on endoscopy and tympanometry. Patients with bilateral symptoms had longer mean symptom duration than patients with unilateral symptoms (8.5 vs. 6.1 months; p < 0.001) and patients with sinusitis symptoms were more likely to have bilateral symptoms compared to those without (76.6% vs. 59.1%; OR = 0.442 [95% CI: 0.330, 0.651]; p < 0.001).

Our group has identified five data-driven symptom cluster groups that may be translated into clinical practice.