Validity and Reliability of the Glottal Function Index

Abstract

To evaluate a symptom-focused vocal impairment instrument for the evaluation of patients with voice disorders. Design: Prospective, nonrandomized study of patients with voice disorders undergoing treatment with validation of a new symptom index, the Glottal Function Index (GFI). Setting: Voice disorders clinic at an academic tertiary care hospital. Patients: Consecutive patients undergoing therapy for glottal insufficiency, adductor spasmodic dysphonia, nodules, and granuloma (40 patients in each group) and 40 control patients. Interventions: The Pearson correlation coefficient was used to evaluate GFI reproducibility and to compare it with the Voice Handicap Index (VHI). The pairedsamples t test was used to compare pretherapy and posttherapy GFI values. Main Outcome Measures: Correlation of GFI with VHI; comparison of the GFI in normals, and in pretherapy and posttherapy GFI and VHI scores. Results: The mean ± SD normative GFI score was 0.87 ±1.32. The correlation coefficient for GFI between independent pretherapy measurements was 0.56 (PϽ.001). The correlation coefficient between total GFI and total VHI scores was 0.61 (PϽ.001). The mean posttherapy GFI scores improved among all groups as follows:

Type I Gore-Tex Laryngoplasty for Glottic Incompetence in Mobile Vocal Folds

“…10 The GFI is a validated, patient-completed, four-item, six-point (0-5) symptom index for GI (range: 0-20, with higher score meaning worse perceived glottal function). 11 The VRQOL is a validated, patient-completed, 10-item, fivepoint instrument that measures the physical and social/emotional impact of dysphonia. 12 Scores are converted to 0-100, with higher scores indicating better VRQOL.…”

Exploring the feasibility of smart phone microphone for measurement of acoustic voice parameters and voice pathology screening

“…In 2005, Bach et al developed and validated the Glottal Function Index (GFI) questionnaire-easily self-administered and reliable 4-item battery that was designed to assess the presence and degree of vocal dysfunction in adults [13]. Subsequently, culturally adapted and validated Lithuanian version of GFI (GFI_LT) was confirmed to be a valid and reliable tool for self-assessment of the severity of voice disorders in Lithuanian-speaking patients [14].…”

Fusing voice and query data for non-invasive detection of laryngeal disorders

“…Rules, extracted by the affinity analysis, highlighted 17 most important query items. Very useful were GFI (Bach et al, 2005;Pribuisiene et al, 2012) items (questions # 22-25), where answering no problem to any of them together with voice handicap progressing of grade 2 and no smoking history was a cue for a healthy larynx, but answering all GFI questions with a non-zero response together with a short duration (2-12 s) of maximum phonation time was a powerful indicator of laryngeal disorder. Short phonation time alone and in combination with zero cigarettes per day or daily voice usage indicated disordered larynx (see pathological rules # 3, 4, 6).…”