Voice Disorders, Stress, and Indoor Environmental Quality: A Cross-Sectional Study of Finnish Teachers

Voice disorders are common in teachers. In addition to the extensive use of their voice, voice problems are associated with stress, a poor indoor environmental quality (IEQ), and frequently also with a decreased work ability. However, epidemiological data on these problems are scarce, and there is little information on the interaction between voice disorders, stress, and the IEQ concerning the work ability of teachers.
The overall purpose of this thesis was to study the variables associated with voice disorders, especially the stress at work, a poor IEQ, and the work ability of teachers. A cross-sectional study was conducted with 1 198 primary and secondary school teachers in three cities across Finland (81% females, 19% males). Voice disorders were assessed with a voice screening questionnaire. The stress at work and work ability were measured with validated, single-item questions. The indoor environment was assessed by using the MM 040 questionnaire, and a technical assessment of school buildings was utilized in relation to a subsample of 538 teachers.
The prevalence of voice disorders over the 12-month period was 54%, and stress was most significantly associated with voice disorders (OR 3.6). Teachers with voice disorders reported more indoor environmental complaints, such as noise and stuffy air, than those without voice disorders. The results also indicated a possible association between a poor condition of school buildings and voice disorders, and there was an agreement between perceived and technical assessments. Work ability was the best in the teachers without voice disorders or stress, and the prevalence of sick leaves was also the lowest in this group. Stress and voice disorders together had a stronger association with a decreased work ability than when they were evaluated separately. Voice disorders, stress, and the perceptions of a poor indoor environment, such as stuffy air and dust, were all clearly associated with work ability.
This study advances our understanding of teachers’ work ability that particularly highlights the relation between voice disorders, stress at work, and a poor IEQ for their work ability. Follow-up studies are needed to investigate the causality of these three variables for work ability. In order to better maintain teachers’ work ability, special attention should be paid to their occupational health, when there are problems rising from the IEQ, and the teachers suffer from voice disorders and stress at work.