Objective: To develop and validate a novel patient-reported outcome measure (PROM) to distinguish patulous from obstructive Eustachian Tube Dysfunction (ETD). To determine accuracy of PROMs and ET function tests as diagnostic tools for ETD.
Study design: 1) PROM development and validation. 2) Test case-control diagnostic accuracy study.
Interventions: Cambridge ETD Assessment (CETDA) and ETDQ-7 PROMs, sonotubometry and tubomanometry ET function tests.
Setting: Tertiary referral center.
Patients: Cases with patulous (n = 7) or obstructive (n = 60) ETD, controls with either no ear symptoms (n = 33), or symptoms arising from hearing loss or Menière's disease (n = 24).
Main outcome measures: PROMs were assessed in terms of internal consistency, ceiling and floor effects, test-retest reliability and content, structural and criterion validity. PROMs and function test sensitivity and specificity was determined as diagnostic tests for ETD.
Results: The 10-item CETDA was developed. CETDA validity and performance were good, though five items suffered floor effects. There was no difference in scores for either PROM in the patulous ETD, obstructive ETD, and symptomatic control groups. Both PROMS had excellent diagnostic accuracy using only healthy controls as comparator for ETD, but specificity was very poor when controls with other otological disorders were included. Both objective tests had sensitivity and specificity of 63% and 79% for obstructive ETD.
Conclusions: The CETDA and ETDQ-7 are not disease-specific and cannot distinguish obstructive from patulous ETD subtypes. A relatively weak correlation between sonotubometry and tubomanometry results, PROM scores, and the clinical diagnosis suggests that a varied core set of outcome measures is required to monitor response to treatments for ETD.