A Comparison of the VHI, VHI-10, and V-RQOL for Measuring the Effect of Botox Therapy in Adductor Spasmodic Dysphonia

Background. Although disease-specific quality-of-life (QOL) instruments are an invaluable outcome measure in spasmodic dysphonia, there is no consensus on which QOL instrument should be used. Objective. To determine the responsiveness of the Voice Handicap Index (VHI), Voice Handicap Index-10 (VHI-10), and Voice-Related Quality of Life (V-RQOL) to the treatment effect of botulinum toxin (Botox) in adductor spasmodic dysphonia (ADSD). Setting. Stanford University Voice and Swallowing Center. Design. Prospective case series (level of evidence 4). Methods. Consecutive ADSD patients with a stable Botox dose-response relationship were recruited prospectively. VHI, VHI-10, and V-RQOL scores were obtained pretreatment and during the middle third of the posttreatment injection cycle. Results. Thrity-seven patients completed the follow-up. The average total Botox dose was 0.88 units. The average follow-up time after injection was 7.84 weeks. The pretreatment QOL scores reflected the burden of the disease. All the three instruments were highly correlated in subscale and total scores. After treatment, all three instruments showed significant improvement. Conclusion. The VHI, VHI-10, and V-RQOL all reflected the morbidity associated with ADSD and were significantly responsive to the effect of Botox therapy. The choice of instrument should be based on physician preference.