Validity and reliability of grade scoring in exercise-induced laryngeal obstruction

Abstract

Introduction: Exercise induced laryngeal obstruction (EILO) is now recognized as a prevalent cause of exertional dyspnoea in the young. Continuous laryngoscopy during exercise (CLE) is the gold standard for the diagnosis of EILO. We aimed to evaluate the diagnostic reliability of CLE and the widely adopted grade scoring approach in the assessment of EILO. Methods: We recruited 23 subjects (17 with EILO and 6 controls). Subjects underwent 4 consecutive treadmill CLE tests, all performed over 4 weeks under identical conditions. Laryngoscopic video recordings were then anonymized, prior to being graded by three raters blinded to subject clinical characteristics. Two months after the initial scoring session, the videos were re-randomised and the rating process repeated for intra-rater agreement. Results: A total of 20 subjects (16 cases and 4 controls) completed four CLE tests. Time to exhaustion was shorter in the first CLE compared with subsequent tests (P Conclusion: Whilst CLE testing is key in the diagnostic assessment of EILO this study reveals that the widely adopted grade scoring system is not a robust means for reliably classifying severity of EILO. Fully objective methods are needed to characterise EILO.