The Effectiveness of Vocal Health Programs in the Prevention of Voice Disorders in Teachers: A Systematic Review and Meta-Analysis

Journal of Voice

Ramos, L. A., Ribeiro, C. J. S., et al. (2025).

Journal of Voice, 39(2), 564.e1-564.e21.

<div>This systematic review and meta-analysis investigates the outcomes of indirect and direct voice disorder prevention programs for teachers without current vocal complaints.</div>

CAPES Foundation (Brasil)

January 2001 to February 2022

<div>Randomized controlled trials and quasi-experimental studies</div>

26

<div>The following findings were demonstrated regarding direct and indirect voice disorder prevention programs for teachers without current vocal complaints:</div> <ul> <li><strong>Voice Handicap Index (VHI):</strong> General, non-significant effects on VHI scores were noted following both direct and indirect training (High Quality of Evidence).</li> <li><strong>Voice-Related Quality of Live (V-RQOL):</strong> One study demonstrated favorable results on V-RQOL scores for direct interventions, while another study demonstrated superiority of indirect interventions. Overall, treatment effects were found to be not significant when compared to no treatment (Very Low Quality of Evidence).</li> <li><strong>Maximum phonation time (MPT):</strong> Results were mixed regarding the impact of direct interventions on MPT. Two studies demonstrated no significant effects of treatment, one study demonstrated significant results in favor of direct training versus no treatment, and one study reported superior outcomes for the no treatment control group. No studies investigated MPT outcomes following indirect treatment (Low Quality of Evidence).</li> <li><strong>Fundamental frequency (f0):</strong> No study demonstrated results supporting the superiority of either direct or indirect treatments for f0, however, "data implied a non-significant superiority" of treatment versus no treatment (p. 564.e5; Very Low Quality of Evidence).</li> <li><strong>Shimmer:</strong> One study demonstrated reduced shimmer for direct interventions, while another study demonstrated superiority of indirect interventions. Overall, treatment effects were found to be not significant when compared to no treatment (Very Low Quality of Evidence).</li> </ul> <div>Overall, findings demonstrated that there was no statistically significant benefit of providing preventative voice disorder training to teachers without current voice complaints. Further research is indicated due to the overall low quality of research with significant risk of bias.</div>