(1)
Departamento de Fundamentos da
Fonoaudiologia e da Fisioterapia da
PUC-SP, São Paulo, SP, Brasil.
(2)
Hospital do Servidor Público Municipal
de São Paulo; Divisão de Educação
e Reabilitação dos Distúrbios da
Comunicação (Derdic-PUC-SP), São
Paulo, SP, Brasil.
(3)
Pontifícia Universidade Católica de São
Paulo – PUCSP, São Paulo, SP, Brasil.
(4)
Departamento de Epidemiologia
da Faculdade de Saúde Pública da
Universidade de São Paulo, São Paulo,
SP, Brasil.
Allowance source: CAPES scholarship
Conict of interest: non-existent
Voice disorder and teaching work ability
Distúrbio de voz e trabalho docente
Léslie Piccolotto Ferreira
(1)
Susana Pimentel Pinto Giannini
(2)
Nássara Luiza Lanzoni Alves
(3)
Aline Ferreira de Brito
(1)
Bruna Mateus Rocha de Andrade
(1)
Maria do Rosário Dias de Oliveira Latorre
(4)
Received on: December 30, 2015
Accepted on: May 15, 2016
Mailing address:
Aline Ferreira de Brito
Rua Icaraí, número 161, bairro Farolândia,
Aracaju – SE, Brasil
CEP: 49032-380
E-mail: alinebrito.fono@gmail.com
ABSTRACT
Purpose: to analyze the association between voice disorder and work ability in teachers of municipal
schools of São Paulo.
Methods: teachers who looked for speech therapy, with voice alteration complaint; and selected tea-
chers with no complaint who were exposed to the work environment and submitted to the auditory voice
perception; completing the Ability Index for the job and the Teacher Condition Vocal Production proto-
cols; and visual-perceptual larynx evaluation. Those with changes in perceptual evaluation and vocal folds
(167) and the control without changes in evaluations (105) were classied as Case.
Results: the ability to work was from low to moderate among the cases (67.4%) and between good and
great (66.6%) in the control teachers (total score). There was statistical association in two dimensions of
ICT, pointing out that teachers with voice disorders had nearly three times more likely to lose the ability to
work and the loss of capacity, and how worst the loss of capacity, the stronger is the association with the
speech disorder.
Conclusion: there is an association between the voice disorder and the dimensions for current work ability
compared with the best of lifetime, indicating that subjects who had a voice disorder was at their worst
ability to work, and estimated loss for work because of diseases, indicating that the greater the loss of
ability to work, the stronger the relationship with the voice disorder, regardless of age.
Keywords: Voice Disorder; Faculty; Work Ability Evaluation; Work; Voice; Speech, Language and Hearing
Sciences
RESUMO
Objetivo: analisar a associação entre distúrbio de voz e capacidade para o trabalho em docentes da rede
municipal de ensino de São Paulo.
Métodos: professoras que buscaram atendimento fonoaudiológico, com queixa de alteração vocal; e
professoras selecionadas sem queixa, expostas ao mesmo ambiente de trabalho, passaram por avalia-
ção perceptivo-auditiva da voz; preenchimento dos protocolos Índice de Capacidade para o trabalho e
Condição de Produção Vocal do Professor; e avaliação perceptivo-visual da laringe. Foram classicadas
como Caso as que tinham alteração na avaliação perceptivo-auditiva e em pregas vocais (167) e Controle
as sem alterações nas avaliações (105).
Resultados: a capacidade para o trabalho esteve entre baixa e moderada entre os casos (67,4%) e entre
boa e ótima (66,6%) nas professoras do controle (escore total). Houve associação estatística em duas
dimensões do ICT, apontando que as docentes com distúrbio de voz apresentaram quase três vezes mais
chance de perder capacidade para o trabalho e que quanto pior a perda da capacidade, mais forte é a
associação com o distúrbio de voz.
Conclusão: há associação entre o distúrbio de voz e as dimensões capacidade atual para o trabalho
comparada com a melhor de toda vida, indicando que os sujeitos que apresentaram distúrbio de voz
estavam em sua pior capacidade para trabalhar, e perda estimada para o trabalho por causa de doenças,
indicando que quanto maior a perda da capacidade para o trabalho, mais forte é a relação com o distúrbio
de voz, independente da idade.
Descritores: Distúrbios da Voz; Docentes; Avaliação da Capacidade de Trabalho; Trabalho; Voz;
Fonoaudiologia
Original articles
Rev. CEFAC. 2016 Jul-Ago; 18(4):932-940 doi: 10.1590/1982-0216201618421615
Rev. CEFAC. 2016 Jul-Ago; 18(4):932-940
Voice disorder and teaching work ability |
933
INTRODUCTION
Teachers belong to the professional category with
higher prevalence of vocal disorders and these injures
are one of the leading causes of work absence, coming
in second only to the psychic disorders
1
.
The development of vocal disorder arising from the
occupational use of voice has been shown in recent
studies, associated with unfavorable conditions of the
environmental and the school-work organization
2
, which
has led to the inability of teachers for the performance
of their duties and has caused them to get involved in
economic and social burden. An early diagnosis may
favor the adoption of measures to protect, prevent and
treat voice disorders in teachers, in addition to save
time and resources
3
.
According to the International Labor Organization
(ILO), teachers are the working category that presents
the greatest risk of contracting work-related voice
diseases and the ILO recommends that these issues
related to teachers are treated as privileged object of
research in the Worker Health eld
4
. In this context,
it is important to have a tool available to evaluate the
perception of the employee with respect to their feeling
while performing their work, in accordance with the
requirements, and with their health condition and
physical and mental capacities. This is the purpose
of the Work Ability Index (WAI), which is a result of
researches conducted in Finland, and has been used
to diagnose and monitor changes in the work ability in
different occupational groups
5
. The WAI contributes to
the study to evaluate work ability through its predictive
value for disability, health/disease and mortality
6
.
The evaluation analyzes the physical and mental
demands of the work, as well as the worker’s health
condition and their physical and mental abilities in order
to detect changes in the work ability. This tool can be
used as a method to assess the work ability in on-site
health tests and to identify workers who need an early
assistance, by predicting the risk of work inability in the
near future, regardless of age
6
.
In Brazil, WAI has been used in different areas for
studies in specic populations; while internationally it is
used in a greater numbers of researches in the medical
eld
7
.
Despite the relevance in the current context of
demographic transition and changes in the business
world, issues regarding work ability in Brazil still
require further attention. There is need to disseminate
knowledge with a number of workers involved with the
situation, so that the subject can be incorporated to the
reality of the business world
8
.
Based on these assumptions, and in order to
present the worker’s assessment on their own work
ability, this study was aimed to analyze the association
between voice disorder and work ability in teachers
from the public schools in São Paulo, through the Work
Ability Index (WAI).
METHODS
This research was conducted from a database
of data collected for the study with teachers of child,
elementary and middle education of the public
education system of São Paulo
9
, and it was approved
by the Research Ethics Committee of the Pontical
Catholic University of São Paulo under the number
061/2011. All participants received elucidation and
signed the free and informed consent.
This case-control study was conducted with 272
teachers, and the option of including only female partic-
ipants was due to the fact that women represent a large
majority in the population of Brazilian basic education
system, according to census data from the National
Institute for Educational Studies and Research
10
.
The selection of participants included two phases. In
the rst phase, all teachers who attended the clinic with
vocal change complaints from July/2007 to May/2009
were selected. Then, teachers underwent to vocal and
laryngoscopic assessments and answered question-
naires. In the second phase, researchers went to the
schools where the case teachers worked and randomly
selected teachers without vocal complaints who were
working and who were subjected to the same proce-
dures from the previous phase. Teachers with organic
vocal fold disorders not related to the use of voice and
those who were not actively performing classroom
functions for medical reasons were excluded from the
sample.
Sample collections for voice evaluation were
performed by speech-language pathologists, early in
the morning, to ensure vocal rest at night. The option
of conducting a perceptive-auditory analysis using the
GRBASI scale (Grade, Roughness, Breathiness, Asteny,
Strain, Instability) was given since this is the standard
procedure in international vocal assessments and due
to its high level of reliability
11
. Considering that most
teachers present voice changed, even in low levels,
voice was classied as altered when the alteration
was moderate (grade 2) or intense (grade 3), and not
altered when normal (grade 0) or mild (grade 1). The
Ferreira LP, Giannini SPP, Alves NLL, Brito AF, Andrade BMR, Latorre MRDO Voice disorder and teaching work ability
Rev. CEFAC. 2016 Jul-Ago; 18(4):932-940
934
| Ferreira LP, Giannini SPP, Alves NLL, Brito AF, Andrade BMR, Latorre MRDO
collection of data related to the larynx was performed
by the otolaryngologist who conducted the video laryn-
goscopy and who classied participants as altered,
when lesions, irritative structural disorders, or chinks in
the vocal folds were detected; and not altered, in the
absence of any lesions or disorders.
Case denition was based on the results of both
vocal and laryngoscopic assessments. The case group
comprised teachers that presented changes in both
assessments (167 participants); while the control group
included participants without changes (105 partici-
pants). Teachers who presented changes in only one of
the two assessments were excluded from the study in
order to obtain groups that were clearly distinct catego-
rized by the illness focused on in this study, even if the
disorders have been accepted for treatment.
For this study, the variables related to the completion
of two instruments were used: (1) the Conditions of
Vocal Production of Teachers (CPV-P) and (2) The
Work Ability Index (WAI).
The CPV questionnaire-P, proposed by Ferreira
et al. (2007)
12
, collects socio-demographic, lifestyle,
occupational, environmental, and school-work organi-
zation data. The answers were given on a Likert scale:
never, seldom, sometimes, and always.
The WAI version used was translated and validated
by researchers from several Brazilian institutions
13
.
It is composed of seven dimensions: current work
ability compared to the best in life, work ability in
relation to work demands, current number of self-
reported diseases or of illnesses diagnosed by a
doctor from a list of 51 illnesses, estimated loss of
work due to illnesses, work absences due to illnesses;
own prognosis concerning work ability; and mental
resources to enjoy daily activities, to feel active and
aware, and to have hopes for the future. The score is
calculated as the sum of points scored for each of the
seven dimensions, namely: 7 to 27 corresponds to low
ability, 28 to 36 to moderate ability, 37 to 43 to good
ability, and 44 to 49 to excellent work ability
6
.
This study analyzed variables regarding socio-
demographics (age, marital status) and teaching
(education, number of schools, time in profession,
type of work contract, number of teaching hours per
week) characteristics. The dependent variable was the
presence of voice disorder (yes=case; no=control),
and the independent variable of interest was the
WAI general score and its seven dimensions; the
independent variable of control was the age. The WAI
general score had a Cronbach alpha coefcient of 0.75
showing good reliability for the instrument in this study.
A chi-square association test with Yates correction
coefcient was conducted for data analysis to
determine the association between the variables of
each dimension of WAI and the presence of a voice
disorder. Then, the association level between these
variables and the voice disorder was determined
through the multivariate logistic regression model, with
the calculation of the Odds Ratio (OR). The variables
with p<0.200 were selected for multiple modeling in
the univariate analysis and the stepwiseforwardse-
lection modeling process was selected. Variables that
remained signicant (p<0.050) were maintained, after
adjusting for other variables.
RESULTS
Socio-demographic data show that the majority is
married, over 40 years old and has complete higher
education. As teachers, they work as full teacher, with
more than 31 working hours per week and they have
over 16 years of professional activity.
Rev. CEFAC. 2016 Jul-Ago; 18(4):932-940
Voice disorder and teaching work ability |
935
The association values of WAI with case and control
groups are shown in Table 3. In ve dimensions of
the instrument the case group presented the highest
number of teachers in the tertile indicative of low work
ability.
Table 2 indicates the analysis of the association
between the total score of the WAI and the voice
disorder between the case and control groups
(p<0.001). It is possible to notice that 66.6% of subjects
in control group considered their work ability as good or
excellent, whereas 67.4% of subjects in the case group
considered their work ability either poor or moderate.
Table 1. Distribution of case and control groups according to socio-demographic characteristics and functional work situation
Socio-demographic characteristics
and functional situation
Controls (n = 105) Cases (n = 167)
p value (χ
2
)
n % n %
Age range 20-29 years old 15 14.3 21 12.6 0.092
30-39 years old 38 36.2 50 29.6
40-49 years old 33 31.4 77 46.4
50-65 years old 19 18.1 19 11.4
Marital status single 27 25.8 49 29.3 0.513
married 62 59.0 100 59.9
divorced/widowed 16 15.2 18 10.8
Education
Incomplete higher
education
4 3.8 13 7.8 0.187
Complete higher
education and more
101 96.2 154 92.2
Time of <10 years 33 31.7 40 24.0 0.244
profession 11-15 years 23 22.1 29 17.4
16-20 years 29 27.9 62 37.1
>21 years 19 18.3 36 21.5
Employment Full Professor 101 96.2 158 94.6 0.552
Substitute Teacher 4 3.8 9 5.4
Classes/ <10 hours 14 13.3 29 17.4 0.187
week 11-20 hours 16 15.2 22 13.2
21-30 hours 32 30.5 31 18.6
31-40 hours 24 22.9 48 28.7
>41 hours 19 18.1 37 22.2
Chi-square test and univariate binary logistic regression (p ≤ 0.05).
Table 2. Association analysis of the WAI general score with case and control groups
Work Ability Index (WAI)
Controls (n = 105) Cases (n = 167) p value (x
2
)
n % n %
Ability
Low 6 6.9 26 17.7
<0.001
Moderate 26 26.4 73 49.7
Good 45 51.7 41 27.9
Great 13 14.9 7 4.8
Chi-square test (p ≤ 0.05).
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| Ferreira LP, Giannini SPP, Alves NLL, Brito AF, Andrade BMR, Latorre MRDO
Table 3. Association analysis between the Work Ability Index with case and control groups
Controls (n = 105) Cases (n = 167)
p (x
2
)
n % n %
Current work ability compared to the best in life
0 – 6 14 13.3 51 30.5 0.001
7 – 8 54 51.4 81 48.5
9 – 10 37 35.2 35 21.0
Work ability in relation to work demands
3 – 7.9 35 33.3 79 47.3 0.050
8 – 8.9 38 36.2 54 32.3
9 – 10 32 30.5 34 20.4
Current number of illnesses diagnosed by a doctor
No illnesses 32 30.5 31 18.6 0.052
From one to three illnesses 45 42.9 75 44.9
Four or more illnesses 28 26.7 61 36.5
Estimated loss of work due to illnesses
There is no loss / I have no illnesses 32 32.7 23 14.2 <0.001
I’m able to perform my work, but it causes me some
symptoms / sometimes I need to reduce my work rate or to
change my working methods
54 55.1 94 58.0
I often need to reduce my work rate or to change my working
methods / due to my illness I feel able to work only part time /
in my opinion, I’m totally unable to work
12 12.2 45 27.8
Work absences due to illnesses (12 months)
No day 33 33.0 37 22.7 0.154
Up to nine days 37 37.0 71 43.6
From ten to twenty-four days 21 21.0 30 18.4
Twenty-ve days or more 9 9.0 25 15.3
Own prognosis concerning work ability in a couple of years
Unlikely 4 4.0 7 4.4 <0.001
I’m not too sure 21 20.8 74 46.3
Likely 76 75.2 79 49.4
Mental resources (0-6 = worst, 10 – 12 = best)
0 – 6 16 16.0 46 28.0 0.011
7 – 9 31 31.0 60 36.6
10 – 12 53 53.0 58 35.4
Chi-square association test and univariate logistic regression with Yates correction coefcient. (p ≤ 0.05).
Table 4 indicates the results of the multivariate
logistic regression analysis adjusted for the age
variable. The difference between case and control
groups stands out in the current work ability compared
with the best of lifetime, estimated loss for work due to
illnesses, work absences due to illnesses in the last 12
months and mental resources dimensions, always with
the worst score for the case group. The dimensions of
work absences due to illnesses in the last 12 months
and mental resources also differed in the groups, but
not remained in the nal model.