Assessment of the Reliability of the Fiberoptic Endoscopic Evaluation of Swallowing as an Outcome Measure in Patients Undergoing Revision Anterior Cervical Discectomy and Fusion

Dysphagia is one of the most common complications of anterior cervical spine surgery, and there is a need to establish that the means of testing for it are reliable and valid. The objective of this study was to measure observer variability of the fiberoptic endoscopic evaluation of swallowing (FEES) test, specifically when used for evaluation of dysphagia in patients undergoing revisionary anterior cervical decompression and fusion (ACDF). Images from patients undergoing revision ACDF at a single institution were collected from May 1, 2010, through July 1, 2014. Two senior certified speech pathologists independently evaluated the swallowing function of patients preoperatively and at 2 weeks postoperatively. Their numeric evaluations of the Rosenbeck Penetration-Aspiration Scale and the Swallowing Performance Scale during the FEES were then compared for interrater reliability. Positive agreement between raters was 94% for the preoperative Penetration-Aspiration Scale (prevalence-adjusted bias-adjusted κ, 0.77). The postoperative Penetration-Aspiration Scale showed reliability coefficients for κ, Kendall's W, and intraclass correlation coefficient (ICC) of 0.34 (fair agreement), 0.70 (extremely strong agreement), and 0.35 (poor agreement), respectively. The preoperative Swallowing Performance Scale showed strong agreement, with a Kendall's W coefficient of 0.68, and fair reliability, with an ICC of 0.40. The postoperative Swallowing Performance Scale indicated extremely strong agreement between raters, with a Kendall's W of 0.82, and good agreement, with an ICC of 0.53. The FEES test appears to be a reliable assessor of dysphagia in patients undergoing ACDF and may be a useful measure for exploring outcomes in this population.