Effectiveness of Intensive Voice Therapy Versus Weekly Therapy for Muscle Tension Dysphonia: A Noninferiority Randomised Controlled Trial With Nested Focus Group

Abstract

To investigate the noninferiority of intensive voice therapy and compare its effects with weekly voice therapy on multidimensional outcomes of voice and well-being, satisfaction, and attendance in people with muscle tension dysphonia (MTD). The study further aimed to explore clinician's perceptions of barriers and enablers to implementation of intensive therapy. Noninferiority randomised controlled trial with nested focus group. Twenty adults with MTD were randomised to receive either weekly voice therapy (1 hour per week for 8 weeks) or intensive voice therapy (1 hour, 4 days per week for 2 weeks). Participants were assessed by a blinded assessor twice before treatment, once post treatment and once at 4 weeks follow up on the primary outcome measure VHI and a range of secondary auditory-perceptual, acoustic, and patient (i.e., VoiSS, satisfaction) and clinician reported outcome measures (i.e., AusTOMs, attendance rates). Five Speech Language Pathologists also participated in a focus group to explore barriers and enablers to implementing intensive therapy, with questions and analyses guided by the Theoretical Domains Framework. While noninferiority for the primary outcome measure VHI was not confirmed, secondary outcome measures revealed comparable within group clinically important improvements for VoiSS and the AusTOMs, as well as selected acoustic and auditory-perceptual measures for both groups. A trend of more improvements being maintained in the intensive group was identified. Comparably high satisfaction and attendance was also found between groups. Clinicians reported more enablers than barriers to providing intensive therapy which included beliefs that it led to greater progression and consolidation of patient learning, was supported by the local context and was associated with positive emotions. Barriers related to difficulties with booking and scheduling and the belief that intensive therapy was not for all patients. While the current study was likely underpowered to establish non-inferiority of intensive therapy, secondary outcomes suggested that intensive therapy may produce comparable benefits to voice, wellbeing, satisfaction and attendance compared to weekly therapy and may be a viable therapy option for individuals with MTD. When implementing intensive therapy, clinicians should consider patient's preferences and availability, as well as systems which allow for flexible booking and therapy provision for patients. Clear recommendations for future research including the use of a larger sample and telehealth are also provided.