The reliability of the assessment of endoscopic laryngeal findings associated with laryngopharyngeal reflux disease

Objective: To determine the reliability of the assessment of laryngoscopic findings potentially associated with laryngopharyngeal reflux disease (LPRD). Study Design: Prospective randomized blinded study. Methods: One hundred twenty video segments of rigid fiberoptic laryngeal examinations were prospectively analyzed by five otolaryngologists blinded to patient information and were scored according to several variables potentially associated with LPRD. Separate assessments of the degree of erythema and degree of edema were scored on a five-point scale for the anterior commissure, membranous vocal fold, and interarytenoid region. Similarly, interarytenoid pachydermia, likelihood of LPRD involvement, and severity of LPRD findings were assessed. For each of these scored physical findings, inter-rater and intrarater reliabilities were determined. Results: The inter-rater reliabilities of the laryngoscopic findings associated with LPRD were poor. Intraclass correlation coefficients were 0.161 and 0.461 for edema of the arytenoids and membranous vocal folds, respectively (P <.001). Intraclass correlation coefficients were 0.181 and 0.369 for erythema of the arytenoids and membranous vocal folds, respectively (P <.001). Raters demonstrated poor agreement as to the severity of LPRD findings (intraclass correlation coefficient, 0.265) and the likelihood of an LPRD component for dysphonia (intraclass correlation coefficient, 0.248). Similarly, intrarater reliability was extremely variable for the various physical findings, with Kendall correlation coefficients ranging from -0.121 to 0.837. Conclusions: Accurate clinical assessment of laryngeal involvement with LPRD is likely to be difficult because laryngeal physical findings cannot be reliably determined from clinician to clinician. Such variability makes the precise laryngoscopic diagnosis of LPRD highly subjective.