Abstract
Background: Flexible nasendoscopy is the principle method of assessment
of vocal cord movement. As this procedure is inherently subjective it
may be that it is not possible for clinicians to grade degree of vocal
cord movement reliably. Aim: The aim of this study was to assess the
accuracy and consistency of grading of vocal cord movement viewed via
flexible nasendoscopy. Design: Prospective video analysis study.
Methods: Thirty flexible nasendoscopy videos, without sound or clinical
information, were assessed by 6 consultant Head and Neck surgeons. They
were asked to assess and grade right and left vocal cord movement
independently, based on a 5-category scale. This process was repeated
three times at separate time intervals. Agreement and reliability were
assessed. Participants: 6 consultant head and neck surgeons. Results:
The mean overall percentage of observed inter-rater agreement was 67.7%
(SD 1.9) with the 5-categories scale, increasing to 91.4% ( SD 1.9)
when a 3-category scale was derived. The mean overall percentage of
observed intra-rater agreement was 78.3% (SD 9.7) for 5 categories,
increasing to 93.1% (SD 3.3) for 3 categories. Discriminating vocal
cord motion using the 5-category scale is less reliable (k= 0.52) than
with the 3-category scale (k = 0.68). Conclusion: This study
demonstrates quantitatively that it is challenging to accurately and
consistently grade subtle differences of vocal cord movement as proven
by lesser agreement and reliability when using a 5 point scale instead
of a 3 point scale. It highlights the need to have an objective measure
to help in the assessment of vocal cord movement.