Development and validation of the Exercise-Induced Laryngeal Obstruction Dyspnea Index (EILODI)

• Published in: Journal of allergy and clinical immunology Vol. 149; no. 4; pp. 1437 - 1444
• Main Authors: Olin, James Tod, Shaffer, Monica, Nauman, Emily, Durso, Catherine S., Fan, Elizabeth M., Staudenmayer, Herman, Christopher, Kent L., Gartner-Schmidt, Jackie
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2022
• Subjects: Adolescent; Airway Obstruction - diagnosis; Airway Obstruction - etiology; Asthma, Exercise-Induced - diagnosis; CLE; continuous laryngoscopy during exercise; Dyspnea - diagnosis; Dyspnea - etiology; EILO; EILODI; Exercise; Exercise-induced laryngeal obstruction; Exercise-Induced Laryngeal Obstruction Dyspnea Index; Humans; Laryngeal Diseases; paradoxical vocal fold motion; patient-reported outcome measure; Quality of Life; questionnaire; VCD; vocal cord dysfunction; Young Adult; Exercise-induced laryngeal obstruction; EFA; questionnaire; continuous laryngoscopy during exercise; PROM; EILO; patient-reported outcome measure; EILODI; vocal cord dysfunction; Exercise-Induced Laryngeal Obstruction Dyspnea Index; MCID; VCD; paradoxical vocal fold motion; CLE
• ISSN: 0091-6749; 1097-6825; 1097-6825
• DOI: 10.1016/j.jaci.2021.09.027

Exercise-induced laryngeal obstruction (EILO) causes exertional dyspnea and is important for its effect on quality of life, diagnostic confusion with exercise-induced asthma, and health care resource utilization. There is no validated patient-reported outcome measure specific to EILO. We sought to develop, validate, and define a minimal clinically important difference for a patient-reported outcome measure to be used with adolescents and young adults with EILO. A multidisciplinary group created a preliminary measure, modified by a 10-member participant focus group, with 20 items scored along a 5-point Likert scale. A subsequent cohort of participants recruited from a clinic, aged 12 to 21 years, with confirmed EILO by continuous laryngoscopy during exercise testing (1) completed the measure at 3 points in time over 28 days and (2) provided anchoring data in the form of a daily exercise log and categorical self-assessments of clinical improvement. Thirty additional participants without exertional dyspnea served as controls. Two hundred nineteen subjects with mild to severe EILO participated in the exploratory factor analysis, which identified 7 factors within the preliminary outcome measure. After a process of item reduction, a 12-item metric with a total score ranging from 0 to 48 was developed. Mean scores of patients with EILO and healthy controls at baseline were 28.8 ± 7.4 and 4.5 ± 7.4, respectively. A minimal clinically important difference of 6 was determined by comparison of index change with changes in categorical self-assessments of improvement. This is the first patient-reported outcome measure specifically designed for adolescents and young adults with EILO.