A panel of jitter/shimmer may identify functional dysphonia at risk of failure after speech therapy

Background: There are no reliable outcome predictors for functional dysphonia (FD) patients. Objectives: To investigate if any clinical or phoniatric characteristics could identify FD patients at risk of negative outcome after speech therapy. Methods: We retrospectively reviewed the results of 78 FD patients treated with the proprioceptive elastic method. Before and one-month after therapy, patients underwent endoscopy, acoustic analysis with Multi-Dimensional Voice Program, and Voice Handicap Index-10 questionnaire (VHI-10). Negative outcome was the persistence of VHI-10 ≥ 13. Results: 26 FD patients had negative outcome (i.e. VHI-10 ≥ 13) after speech therapy. At univariate analysis, clinical variables (i.e. sex, age, comorbidities, dysphonia duration, and professional voice use) were not associated with the outcome. Elevated Jitter% (Jitt; p = 0.03), Shimmer% (Shim; statistical trend, p = 0.06), and Noise to Harmonics Ratio (statistical trend, p = 0.06) were found in patients with poor results. At multivariate analysis, higher Jitt was an independent negative prognostic factor (p = 0.02), while a statically trend was identified for Shim (p = 0.06). A panel of Jitt >1.5 and Shim >5.1 showed an acceptable discriminatory power (AUC [ROC] = 0.76) according to Hosmer and Lemeshow scale. Conclusion: A panel of two acoustic analysis parameters could help in identifying FD patients at risk of speech therapy failure. Further studies in these patients are needed to evaluate the most efficient treatment protocol.