Is an occupation with vocal load a risk factor for laryngopharyngeal reflux: a prospective, multicentre, multivariate comparative study

Objectives: To compare the prevalence of laryngopharyngeal reflux in choristers, teachers and control subjects without vocal load at work and to determine the risk factors for laryngopharyngeal reflux. Design: A prospective, multicentre, multivariate comparative study. Participants: One hundred and nineteen singers from four professional choirs, seventy teachers from four schools and 111 control subjects with an occupation without vocal load. Main outcome measures: All participants completed a questionnaire about their dietary habits, height and weight, presence of stress, smoking and allergies, including the nine-item Reflux Symptom Index. The groups of choristers, teachers and the controls were compared with each other with regard to their sex, age, dietary habits, body-mass index, Reflux Symptom Index score and other factors affecting voice quality. The subjects from all three groups with suspected laryngopharyngeal reflux were compared with the subjects without it. The relationship between the Reflux Symptom Index score and the possible risk factors for reflux was estimated. Results: The results showed significantly higher Reflux Symptom Index scores in the choristers than in the teachers and the controls (mean scores, 7.86 versus 6.33, P = 0.044; 7.86 versus 4.80, P = 0.000, respectively), but the number of subjects with suspected laryngopharyngeal reflux (Reflux Symptom Index score > 13) did not differ significantly between the groups. The choristers were significantly more often treated for laryngopharyngeal reflux than the teachers and the controls (41%, 17% and 28%, respectively). The occupation chorister and frequently experiencing stress were the only factors that influenced the total Reflux Symptom Index score. Conclusions: Laryngopharyngeal reflux affects the choristers more often than the teachers or the control subjects without vocal load at work. These results suggest that singing as the main professional activity can notably contribute to the development of the reflux. Vocal load without singing is probably not an important aetiological factor for laryngopharyngeal reflux. The extraoesophageal symptoms affecting voice require treatment for laryngopharyngeal reflux and proper dietary habits especially in the group with high voice quality demands.