The Risk Factors of Voice Disorders in Non-University Teachers: A Systematic Review and Meta-Analysis

Teachers are often considered to be at high risk for voice disorders. Many studies have been conducted globally. However, the risk factors included in these studies varied, and even for the same influencing factors, the results were inconsistent across studies. No uniform conclusions have yet been drawn. The aim of this study is to identify the risk factors of voice disorders in non-university teachers and to provide insights for their prevention, treatment, and mitigation of recurrence.

In this systematic review (PROSPERO/CRD42024554265), PubMed, Scopus, Web of Science, Embase, and Wiley were searched up to January 14, 2024. A manual search was performed in gray literature through OpenGrey and ProQuest Dissertations and Theses. There was no limitations to the date of publication and language. Studies with a cross-sectional or case-control design and investigating the risk factors of voice disorders in non-university teachers were included. Two researchers performed separately to select articles, extract data, and evaluate the quality of the included studies. The 95% confidence interval and odds ratio were applied to examine the effect size. A meta-analysis was performed with a random effects model using the Stata 16.0 software.

A total of 23 studies were considered, with a total of 73.609 teachers. The results of this meta-analysis: sex[OR = 1.63, confidence interval (CI) (1.17, 2.28)], smoking[OR = 1.31, CI(1.00，1.72)], upper respiratory tract infections [OR = 2.88, CI(1.59，5.23)], respiratory allergies [OR = 3.02, CI(2.21, 4.10)], endocrine diseases [OR = 2.25, CI(1.52, 3.34)]; acid reflux symptoms [OR = 2.41, CI(1.32, 4.40)], stress [OR = 2.47, CI(1.45, 4.19)], lack of discipline in the classroom [OR = 1.63, CI(1.20，2.20)], physical education [OR = 1.58, CI(1.10, 2.28)], noise in the classroom [OR = 1.89, CI(1.42, 2.53)], excessive speaking [OR = 2.52, CI(1.77, 3.60)], throat clearing [OR = 2.10, CI(1.18, 3.75)], shouting [OR = 1.42, CI(1.02, 1.96)], and speaking loudly [OR = 3.06, CI(1.91, 4.91)] may contribute to the development of voice disorders. Subgroup analyses revealed that the diagnostic tool may contribute to high heterogeneity.

The etiopathology of voice disorders in non-university teachers is frequently complex. Multidimensional diagnosis of voice disorders plays an important role in the study of voice disorders It is imperative to undertake early vocal training and implement preventive measures to prevent the currency of voice disorders.