Introduction
Flexible nasendoscopy (FNE) is the most commonly performed examination used for assessment of vocal cord movement. It is routinely performed on patients with voice complaints and management is frequently based on the findings. FNE is the current gold standard method of evaluation of vocal cord motion, helping to distinguish between normal and reduced vocal cord movement. However, this subjective assessment can lead to inaccuracies and variability in diagnosis, especially in challenging cases. There is no reliable objective measure of categorising vocal cord movement from normal to complete paralysis. Furthermore, limited data exist on how consistent otolaryngologists are at rating vocal cord movement 1,2.
The reliability of clinicians differentiating between binary categories of mobile and immobile vocal cords1,2 and the presence or absence of paresis have been reported3. The former studies reported a 95% inter-rater reliability and a 99% intra-rater agreement for binary vocal cord assessment and the latter an inter-rater reliability of 0.334 (Fleiss’s kappa). A three category scale (paralysis, paresis, normal) was used in reliability studies in paediatric patients4. They reported an inter-rater reliability (Cohen’s kappa) of 0.67 for diagnosis of normal vs impaired movement, and lesser reliability of 0.49 when identifying the degree of movement (normal, paresis, paralysis). The intra-rater reliability ranged from 0.48 to 1 (Fleiss’s kappa). There is currently no reliable grading system for categorising vocal cord movement from normal to complete paralysis, for example similar to the House Brackman scale used to routinely grade facial nerve paralysis.
The aim of this study was to determine if experienced consultant head and neck surgeons were accurate and consistent with their assessment and grading of vocal cord movement.