Reflux symptoms and vocal characteristics in adults with non-organic voice disorders

BACKGROUND: Laryngopharyngeal reflux (LPR) is prevalent and can lead to voice disorders, but its diagnosis is difficult, because of limited correlations between clinical symptoms and organic pathology. Various tools and methods have been explored to aid a diagnosis of LPR. OBJECTIVE: To investigate associations between reflux symptoms, acoustic-, perceptual-, and physical vocal characteristics, glottal function index (GFI), and vocal handicap index (VHI) in adults with non-organic voice disorders. METHODS: Data of 51 adults with non-organic voice disorders were collected, using a retrospective cohort explorative research design, at a private ear, nose and throat specialist practice in Gauteng, South Africa. Quantitative outcomes were compared between reflux symptom index (RSI), acoustic characteristics (jitter, shimmer and fundamental frequency [F0]), maximum phonation time, perceptual- (GRBASI) and physical vocal characteristics, GFI and VHI. RESULTS: The RSI showed positive fair correlations against GFI, VHI(P) and caffeine intake, indicating an increase in reflux symptoms with higher scores on the various measures. Moderate correlations were also found between GFI and VHI(P), grade of hoarseness and jitter, strain and VHI(P), strain and VHI total (VHI(T)) and between Asthenia and jitter. Very strong correlations were found within the various subsections of the VHI as well as between jitter and shimmer and between F0-male and physical symptoms of the VHI (VHI(P)). CONCLUSION: Results indicated associations between reflux symptoms, vocal characteristics, the GFI and the VHI. Based on the correlations found these tools used in conjunction could improve clinical diagnosis of LPR. Implications of these findings are promising, but further research is recommended. CONTRIBUTION: This study contributes to the body of knowledge to support the accurate clinical diagnosis of LPR using subjective measures to determine LPR symptoms, as well as acoustic analysis.