Association between occupational voice use and occurrence of voice disorders: a meta-analysis

Abstract

Purpose: This meta-analysis has two aims: 1) to provide a quantitative assessment of the occurrence of voice disorders among different occupational voice users, 2) and to determine whether being an occupational voice user (teacher, broadcaster, call-center worker, etc.) is associated with an increased occurrence of voice disorders. Method: A random-effect meta-analysis of the available scientific literature was conducted on the occurrence of voice disorders among occupational voice users. Comprehensive literature searches were conducted using two computerized databases: PubMed/MEDLINE, and Scielo. As a measure of association, the odds ratio (OR) with corresponding 95% confidence interval (95% CI) was used. Heterogeneity was assessed by chi-square and I2 and draw in forest plots. Results: Voice disorders are related with occupational voice use independently of type of prevalence with a pool OR of 2.39 for current voice disorders, 1.88 for 12-months prevalence, and 2.43 for life-time and unspecified recall period. Heterogeneity test (I2) among these articles is 68% for current voice disorders, 0% for 12-months voice disorders, and 66% for life-time and unspecified recall period. Although around 70% of the total number of included publications assessed the occurrence of voice disorders among teachers as occupational voice users, an analysis per occupation was performed to identify possible influence of this factor in the occurrence of voice disorders. Studies that include just teachers as the group of occupational voice users (n=12) reported ORs ranging from 1.20 to 4.61. Heterogeneity test (I2) among these articles is 17%. Studies that include telemarketers, newsreaders, and sellers as the group of occupational voice users (n=6) reported ORs ranging from 0.85 when future vocal professionals were compared future non-vocal professionals to 4.58 when newsreaders were compared with non-newsreaders. Heterogeneity test (I2) among these articles is 40%. Conclusion: Occupational voice users have a higher likelihood of having voice disorders. Results of this meta-analysis show that teachers had a slightly lower likelihood (pool OR=1.95) than telemarketers, broadcasters, and sellers (pool OR=2.75) for having a voice disorder regardless the type of prevalence. Nevertheless, due the weak to moderate quality of the included studies, the results should be taken with caution.