title: Epidemiology of voice disorders in teachers and nonteachers in Brazil: prevalence and adverse effects.
abstract: OBJECTIVE
  This epidemiological study compared the frequency and adverse effects of voice disorders in Brazilian teachers and nonteachers.
  
  
  METHODS
  A standardized interview/questionnaire was administered to 3,265 participants; 1,651 teachers; and 1,614 nonteachers recruited from all 27 Brazilian states.
  
  
  RESULTS
  Prevalence of reporting a current voice disorder was 11.6% for teachers and 7.5% for nonteachers, respectively (χ2(1)=16.1, P<0.001). Sixty-three percent of teachers and 35.8% of nonteachers reported having experienced a voice problem at some point during their lifetime (χ2(1)=246.6, P<0.001). Teachers reported a higher number of current (3.7) and past (3.6) voice symptoms as compared with nonteachers (1.7 current, 2.3 past) and more often attributed these symptoms to their occupation (P<0.001). Teachers, as compared with nonteachers (1) more frequently reported that their voice limited their ability to do certain tasks within their current occupation (29.9% of teachers vs 5.4% of nonteachers; P<0.001); (2) experienced more voice-related absenteeism over the past year (12.1% of teachers missed 5 or more days of work vs 2.4% of nonteachers; P<0.001); and (3) more often considered changing occupations in the future because of voice problems (16.7% of teachers vs 0.9% of nonteachers; P<0.001). The magnitude of voice-related dysfunction among teachers was similar across Brazilian states, and regional characteristics did not appear to significantly influence the results.
  
  
  CONCLUSIONS
  This large epidemiological study comparing teachers and nonteachers confirms that teaching at school is a high-risk occupation for developing voice disorders. These voice disorders contribute to reduced job performance, attendance, and force many Brazilian teachers to consider changing occupations in the future because of their voice.
authors.affiliation: Centro de Estudos da Voz-CEV (Center for Voice Studies), São Paulo, Brazil. mbehlau@uol.com.br
authors.forename: Mara
authors.initials: M
authors.lastname: Behlau
authors.forename: Fabiana
authors.initials: F
authors.lastname: Zambon
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Guerrieri
authors.forename: Nelson
authors.initials: N
authors.lastname: Roy
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D005178:Faculty / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D016017:Odds Ratio; D015995:Prevalence; D025341:Principal Component Analysis; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014831:Voice; D014832:Voice Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology