The Degree of Change and Relationship in Self-perceived Handicap and Acoustic Voice Quality Associated With Voice Therapy

Introduction: Outcome measures describing acoustic voice quality and self-perceived vocal handicap are commonly used in clinical voice practice. Previous reports of the relationship between acoustic and self-perceived measures have found only limited associations, but it is unclear if acoustic measures associated with voice quality and self-perceived voice handicap change in a similar manner over the course of voice treatment. The current study, therefore, considered the relationship between the degree of change in Acoustic Voice Quality Index (AVQI) and Voice Handicap Index (VHI-30 and VHI-10) in dysphonic patients receiving treatment in a private practice voice clinic.

Methods: Data were collected retrospectively from patient records of a private practice voice clinic over 80 consecutive months. For each patient, their voice disorder diagnosis, age, and biological sex were collected as well as pre-and post-treatment measures of the AVQI and VHI-30 or VHI-10 depending on which version was used. Correlations were calculated between the AVQI and VHI-30 and the AVQI and VHI-10 before and after treatment as well as for the percentage change of AVQI and VHI-30/VHI-10. Friedman and Kruskal-Wallis tests were used to determine the pre-and post-treatment effect and group differences respectively.

Results: Seventy-eight patients were included in the analyses. The scores of the AVQI (χ²[1] = 24.01, P < 0.001), VHI-30 (χ²[1] = 18.00, P < 0.001), and VHI-10 (χ²[1] = 38.35, P < 0.001) all improved significantly after treatment. However, correlations between the AVQI and VHI-30, and the AVQI and VHI-10 were all non-significant, except for a moderate correlation between the AVQI and VHI-10 before treatment (r[43] = 0.31, P = 0.04). The percentage change of the AVQI and the VHI-30/VHI-10 did not correlate significantly.

Conclusions: Voice therapy significantly improved acoustic and self-perceived vocal outcome measures. However, there was no significant relationship between these measures before or after treatment, nor was there a relationship in their degree of change. Results support the notion that VHI and AVQI measure unique constructs and that voice therapy can have a positive impact on both.