Validation of a Pediatric Vocal Fold Nodule Rating Scale Based on Digital Video Images

Abstract

We sought to create a validated scale of vocal fold nodules in children, based on digital video clips obtained during diagnostic fiberoptic laryngoscopy. We developed a 4-point grading scale of vocal fold nodules in children, based upon short digital video clips. A tutorial for use of the scale, including schematic drawings of nodules, static images, and 10-second video clips, was presented to 36 clinicians with various levels of experience. The clinicians then reviewed 40 short digital video samples from pediatric patients evaluated in a voice clinic and rated the nodule size. Statistical analysis of the ratings provided inter-rater reliability scores. Thirty-six clinicians with various levels of experience rated a total of 40 short video clips. The ratings of experienced raters (14 pediatric otolaryngology attending physicians and pediatric otolaryngology fellows) were compared with those of inexperienced raters (22 nurses, medical students, otolaryngology residents, physician assistants, and pediatric speech-language pathologists). The overall intraclass correlation coefficient for the ratings of nodule size was quite good (0.62; 95% confidence interval, 0.52 to 0.74). The p value for experienced raters versus inexperienced raters was 0.1345, indicating no statistically significant difference in the ratings by these two groups. The intraclass correlation coefficient for intra-rater reliability was very high (0.89). The use of a dynamic scale of pediatric vocal fold nodule size most realistically represents the clinical assessment of nodules during an office visit. The results of this study show a high level of agreement between experienced and inexperienced raters. This scale can be used with a high level of reliability by clinicians with various levels of experience. A validated grading scale will help to assess long-term outcomes of pediatric patients with vocal fold nodules.