Glottal Function Index: A Predictor of Glottal Disorders in Children

Abstract

Hyperkinetic laryngeal behaviors may be used to achieve glottal closure in the presence of vocal cord disorders. In adults, the Glottal Function Index (GFI) is a validated self-administered survey used to evaluate glottal insufficiency. In children, the relationships between glottal closure and vocal cord lesions have not been examined. We undertook to evaluate the efficacy of the GFI in detecting disorders of the vocal cords in children. We evaluated 100 consecutive children who underwent flexible fiberoptic laryngoscopy. A 4-item GFI questionnaire was administered to the parents of each study subject on study entry. The videotapes of the examinations were evaluated and scored by 3 investigators in a blinded manner. The GFI scores were compared in subjects with and without vocal cord findings. The final analysis included 100 children 2 to 16 years of age. The-mean age of the study group was 7.3 years (+/-3.9 years). Of the 100 patients, 54 had vocal cord disorders. The most common was vocal cord nodules, in most cases combined with bowing of the vocal cords; the two variables were highly correlated (p << .01). We performed a receiver operating characteristics test between the presence of vocal cord disorders and the GFI score. We found that the "optimal" score, on which the sensitivity and specificity curves cross, was 3. Of the 54 patients who had vocal cord disorders, the index identified 38 patients (70%), whereas the patients' complaints identified only 30 patients (55.6%). This difference was statistically significant (p < .05). The GFI is a reliable 4-item symptom index with excellent correlation to the presence of vocal cord lesions in children.