Reliability of postoperative photographs in assessment of facial nerve function after vestibular schwannoma resection.

OBJECT: This study was undertaken to assess the reliability of observations of postoperative photographs in assigning House-Brackmann scores as outcome measures for patients following resection of vestibular schwannomas.

METHODS

Forty pictures of differing facial expressions typically elicited from patients for assigning House-Brackmann scores were individually evaluated by neurosurgery residents and faculty members at the University of Alabama at Birmingham; a score was assigned to each picture by the individual raters. The interrater reliability was measured using the Spearman correlation coefficient, Kendall coefficient of concordance, and kappa statistic; internal consistency was calculated using the Cronbach alpha reliability estimate.

RESULTS

The Spearman correlation coefficients showed strong positive association among raters, with a range of values of 0.66 to 0.90. Internal consistency measured by the Cronbach alpha coefficient was excellent (α = 0.97). The Kendall coefficient of concordance for the ordinal grades suggested a substantial degree of agreement among the raters (w = 0.76, p < 0.001).

CONCLUSIONS

Static postoperative photographs are a reliable outcome measure for determining facial nerve function after vestibular schwannoma resection and may serve as a surrogate for the dynamic patient interview.