Objective: As part of a comprehensive study of indications for tonsillectomy and adenoidectomy, we investigated the reliability of standardized clinical assessments and standardized roentgenographic assessments of adenoidal obstruction of the nasopharynx, and the degree of correlation between clinical assessments and roentgenographic assessments.
Methods: We rated the degree of patients' mouth breathing and patients' speech hyponasality on a 4-point scale (none = 1; mild = 2; moderate = 3; marked = 4), we averaged the ratings for each child to obtain a Nasal Obstruction Index, and we determined levels of interobserver agreement concerning the ratings. We classified lateral soft-tissue roentgenograms of the nasopharynx, based on assessments of adenoid size and of nasopharyngeal airway patency, as showing either no obstruction, borderline obstruction, or obstruction, and we determined levels of inter- and intraobserver agreement concerning the classifications. Finally, we determined correlations in individual patients between clinical ratings and roentgenographic ratings of nasal/nasopharyngeal obstruction, and calculated the predictive values of clinical ratings based on roentgenographic ratings as the gold standard.
Results: In sets of paired examinations, weighted kappa values for interobserver agreement concerning mouth breathing (total, 235 children) and speech hyponasality (total, 648 children) ranged from 0.84 to 0.91. The value for interobserver agreement concerning roentgenographic assessment of nasopharyngeal airway status (207 children) was 0.92, and for intraobserver agreement (191 children) 0.88. The Kendall's tau b value for concordance between Nasal Obstruction Index values and roentgenographic ratings (1033 children) was 0.51. Nasal Obstruction Index values at the lower and upper extremes--i.e., 1.0 and > or = 3.5, respectively--were highly predictive of concordant roentgenographic ratings.
Conclusions: We conclude that standardized clinical ratings of the degree of children's mouth breathing and speech hyponasality provide reliable and reasonably valid assessments of the presence and degree of adenoidal obstruction of the nasopharyngeal airway. These clinical assessments are particularly valid at the extremes of either marked obstruction or no obstruction. Clinical assessment alone may be insufficient to establish the presence of adenoidal obstruction, but clinical assessment alone when findings are unequivocally negative can suffice to rule out adenoidal obstruction with a high degree of confidence.