Evaluation of facial function with a questionnaire: reliability and validity.
OBJECTIVE
To analyze the validity and reliability of assigning House-Brackmann facial nerve grade based on a patient-administered questionnaire. Specifically, the use of a questionnaire was studied for evaluation of the long-term facial function after microsurgical resection of vestibular schwannoma (VS).


METHODS
Three neurotologists with more than 25 years of experience and 3 neurotology clinical fellows rated facial nerve grade in a blinded fashion based on the questionnaire. The standard to which the questionnaires were compared was the facial nerve grade assigned to the patient during an office visit near the same time as the completed patient questionnaire.


METHODS
Thirty-four patients had an office evaluation of facial function at least 1 year after microsurgical resection of a VS. Thirty patients had a sporadic VS, whereas 4 patients had neurofibromatosis 2. The average tumor size was 2.2 cm. A postoperative questionnaire regarding facial function was completed within 2 months of the office evaluation. Statistical analyses were performed to compare the office evaluation rating with the questionnaire rating (validity) and to analyze interobserver reliability.


RESULTS
The association between the facial nerve grade assigned by the office evaluation and the questionnaire was highly significant (p<0.01), with a mean correlation (Spearman [rho]) equal to 0.94. The interobserver reliability was high, with coefficients ranging from 0.93 to 0.99 (p<0.01; mean=0.97). Because a large proportion of patients had normal (House-Brackmann Grade I) facial function, an additional analysis was performed with these patients excluded. The high levels of interobserver reliability persisted (average=0.96).


CONCLUSIONS
When compared with office evaluation, a patient-administered questionnaire provides a valid and reliable measure of long-term facial function after VS surgery.
Cullen
Robert D
RD
House Clinic, Los Angeles, CA 90057, USA.
House
John W
JW
Brackmann
Derald E
DE
Luxford
William M
WM
Fisher
Laurel M
LM
D005154:Facial Nerve / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D019635:Neurosurgical Procedures; D015588:Observer Variation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires