[Efficacy of Novafon Local Vibration Voice Therapy and Water Resistance Therapy: a meta-analysis].

Abstract

Treatment approaches for voice therapy are diverse and two treatment approaches in voice therapy with assistive devices will be evaluated and compared for efficacy. Evaluations of the treatment effects of different approaches are important for clinical consultation and evidence-based practice. To evaluate the efficacy of Novafon Local Vibration Voice Therapy (NLVVT) and Water Resistance Therapy (WRT) using Voice Handicap Index (VHI). Systematic literature search and meta-analysis with random effects model. The analysis of two databases (MEDLINE and CENTRAL) and a manual search from inception to September 19th 2021. Any clinical trial with case series in a pre-post design written in English or German that tested the efficacy of NLVVT or WRT using VHI (functional [F], physical [P], and emotional [E] aspects, and total score [T]) in adult voice patients with an organic or functional voice disorder was considered. Five eligible studies were identified (NLVVT n= 22; WRT n= 42). Both treatment approaches showed highly significant improvement in all aspects of the VHI (p-values< 0.01). In direct comparison, NLVVT achieved significantly higher improvements in VHI-T, VHI-F and VHI-E than WRT (p-values< 0.01). Comparable improvement was received in VHI-P (p= 0.28). NLVVT and WRT are effective treatments for voice disorders related to the subjective evaluation of a voice disorder. In direct comparison, NLVVT achieved higher improvements than WRT in most VHI aspects.