Are Occupational Voice Disorders Accurately Measured? A Systematic Review of Prevalence and Methodologies in Schoolteachers to Report Voice Disorders.

Purpose: Different measuring instruments have been described to determine the prevalence of voice disorders in schoolteachers. However, the heterogeneity of prevalence figures has made it difficult in determining the impact of voice disorders in this group. This investigation aims to review and identify scientific evidence of methodological analysis of voice disorders in teachers, the relevance of measuring instruments, the prevalence of dysphonia, and the impact on the development of vocal health prevention programs.

Methods: A systematic review was conducted by searching six important scientific databases. Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines were carried out. Articles were included whether they presented data related to the prevalence of dysphonia and the impact of therapy programs on teachers.

Results: Twenty articles out of 8,998 were selected. The cross-sectional design type was predominant throughout the investigations. Differences were observed in the number of participants across studies, leading to heterogeneous prevalence figures - which ranged from 10.5% to 69.1%. The assessment instruments are not standardly used to effectively determine the disease burden. Despite the fact of the extensive evidence of the effectiveness of programs that address dysphonia in teachers, the scarcity of literature is yet evident on systematic programs promoted by either the government or educational institutions.

Conclusion: Findings suggest that future investigations should consider the consensus of a global definition for occupational dysphonia in teachers in order to develop accurately measuring instruments and to assist with voice care programs and treatment approaches in this population. This might be crucial since it could also assist with the implementation of Delphi-type studies that could support the development of further evidence-based agreements around these programs (voice care and treatment approaches) in schoolteachers.