COMPARISON OF SINUS COMPUTED-TOMOGRAPHY STAGING SYSTEMS

In an attempt to establish a standardized rating system for CT of the paranasal sinuses, the Committee on Rhinology and Paranasal Sinus Dise ase of the American Academy of Otolaryngology-Head and Neck Surgery in stituted a protocol for the review of sinus CT scans at six internatio nal sites, Fifty identical scans were rated by four otolaryngologists at each site according to five established sinus CT staging systems, T wenty of 24 reviewers repeated the rating session at least 1 week late r to determine intrarater variability The number of CT scans that coul d not be classified by a particular rating system ranged from 1.3% to 5.5%, The range of intrarater agreement (kappa = 0.39 to 0.74) exceede d that of interrater agreement (kappa = 0.18 to 0.49), A skewed distri bution of CT scans resulted in a system with high rater agreement but poor ability to differentiate among disease states, The use of a numer ic rating system to assign a score to each scan produced a comprehensi ve and disease-sensitive system, but one with low rater agreement. A p recise definition of mucosal thickening in terms of millimeters appear ed to enhance the raters' ability to assign stage and improve a system 's comprehensiveness and reproducibility. On the basis of these findin gs, recommendations are made for the use of CT rating systems to study clinical outcomes in patients with chronic sinusitis.