Purpose: We determined the natural course of voice complaints among school workers and established the risk factors associated with incidence and chronic voice complaints.
Method: We conducted a longitudinal study with an 11-month follow-up among 682 school workers. Participants filled out a questionnaire on individual and work-related conditions and the nature and severity of voice complaints. All participants who provided baseline data were contacted in the 11-month follow-up, if they were still working in the school. Short-term environmental measurements of physical work-related factors were conducted during visits at the workplaces. Logistic regression analysis was used to determine associations between work-related factors and voice complaints.
Results: We found a high occurrence of chronic voice complaints, a low recovery of 22%, and an annual incidence of 44%. A self-reported high noise level at the workplace was associated with the incidence of voice complaints (odds ratio = 2.45). Self-reported poor acoustics in the classroom was associated with chronic voice complaints (odds ratio = 1.76).
Conclusions: This unique longitudinal study among school workers presented some indications that self-reported high noise levels may contribute to the incidence of voice complaints, whereas self-reported poor acoustic conditions may be an important associated factor of chronic voice complaints.