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Prevalence and Risk Factors for Voice Problems Among Telemarketers
Katherine Jones, MS;
Jason Sigmon, MD;
Lynette Hock, MS;
Eric Nelson, BS;
Marsha Sullivan, MA, CCC-SLP;
Frederic Ogren, MD
Arch Otolaryngol Head Neck Surg. 2002;128:571-577.
ABSTRACT
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Objectives To investigate whether there is an increased prevalence of voice problems
among telemarketers compared with the general population and if these voice
problems affect productivity and are associated with the presence of known
risk factors for voice problems.
Design Cross-sectional survey study.
Settings One outbound telemarketing firm, 3 reservations firms, 1 messaging firm,
1 survey research firm, and 1 community college.
Participants Random and cluster sampling identified 373 employees of the 6 firms;
304 employees completed the survey. A convenience sample of 187 community
college students similar in age, sex, education level, and smoking prevalence
served as a control group.
Main Outcome Measures Demographic, vocational, personality, and biological risk factors for
voice problems; symptoms of vocal attrition; and effects of symptoms on work.
Results Telemarketers were twice as likely to report 1 or more symptoms of vocal
attrition compared with controls after adjusting for age, sex, and smoking
status (P<.001). Of those surveyed, 31% reported
that their work was affected by an average of 5.0 symptoms These respondents
tended to be women (P<.001) and were more likely
to smoke (P = .02); take drying medications (P<.001); have sinus problems (P
= .04), frequent colds (P<.001), and dry mouth
(P<.001); and be sedentary (P<.001).
Conclusions Telemarketers have a higher prevalence of voice problems than the control
group. These problems affect productivity and are associated with modifiable
risk factors. Evaluation of occupational voice disorders must encompass all
of the determinants of health status, and treatment must focus on modifiable
risk factors, not just the reduction of occupational vocal load.
INTRODUCTION
APPROXIMATELY one third of the labor force in industrialized societies
relies on voice as their primary work tool.1
Occupational voice disorders might be the result of the repetitive movement
or "collision" of the vocal folds.1 Vocal attrition
can be described as "the ‘wear and tear' of the vocal mechanism and
the overall reduction in vocal capabilities associated with acute or chronic
abuse of the phonatory system."2(p130) Recent
studies have shown an association between voice problems and vocally demanding
jobs such as teaching,3-6
singing,7-9 and
aerobics instruction.10-11
Vocal attrition and occupational voice disorders are also a result of
the combined effects of vocational, personality (lifelong speech habits),
and biological factors.1-2 Vocational
factors include vocal loading or the vocal demand of the job, background noise,
room acoustics, speaking distance, air quality, posture, stress, and equipment
design.1 Speech-related personality factors
include the tendency of a person to habitually speak loudly, excessively,
and rapidly.2 Biological factors include all
of the factors that may affect the vocal mucosa or the respiratory ability
to support speech, such as smoking,7, 12-13
hydration,12 intake of caffeinated beverages,12-14 medications,12-13,15 respiratory illnesses,
chronic allergic rhinitis, sinusitis,1, 10, 12
gastroesophageal reflux,12-13,16-17
and general physical condition.1
Despite recognition of the existence of occupational voice disorders
and vocal attrition, an objective measure of vocal function similar to the
audiogram for hearing is not available. Furthermore, the ability to quantify
the absolute amount of vocal dysfunction would not describe the impact of
a voice problem on an individual's quality of life.18
Consequently, it is necessary to consider the nature of the voice symptoms
reported by the target population and the impact of those symptoms on work
and social interaction when defining the nature of a voice problem. There
are currently 3 valid and reliable disease-specific outcome measures for use
with populations who have an existing diagnosis of a voice disorder. These
measures are the Voice Handicap Index,19 the
Voice-Related Quality of Life Measure,18 and
the Voice Outcome Survey.20
There are no reliable data on the prevalence of voice disorders in the
general adult population,18 and to our knowledge,
a detailed examination of voice in the telemarketing environment has not been
done. Titze et al21 report that telemarketers
made up 2.3% of the patient volume in a voice clinic but comprised only 0.78%
of the 1994 workforce; indicating that telemarketers were about 3 times as
likely to seek help from a voice clinic than the general population. This
research by Titze et al21 represents the only
literature we found that specifically considers telemarketing in association
with voice problems. We hypothesize that there is an increased prevalence
of voice problems among telemarketers compared with the general population
and that these voice problems affect productivity and are associated with
the presence of known risk factors for voice problems. The 3 validated voice
disorder outcome instruments do not meet our need for the collection of data
on vocational, personality, and biological factors. To test these hypotheses
we designed a 57-item "voice survey" that included questions regarding demographic,
vocational, personality, and biological risk factors for voice problems; symptoms
of vocal attrition; and effects of any voice problem on work and social interaction.
PARTICIPANTS AND METHODS
PARTICIPANTS
This cross-sectional survey research was accomplished by contacting
human resources directors and managers at 19 separate firms in 2 midwestern
cities. After discussing the research topic and hypotheses, 6 firms agreed
to participate in the surveys. The firms who declined to participate cited
a desire to avoid raising employee awareness of voice problems. The surveys
were conducted between August 8 and October 4, 2000. The participating firms
included 1 outbound telemarketing firm, 3 reservations centers, 1 messaging
company, and 1 telephone survey research firm. The employee participants of
these firms are collectively referred to as "telemarketers."
DATA COLLECTION
Random sampling was performed at small firms, and cluster sampling was
performed at larger firms to avoid selection bias. Sampled employees received
letters of invitation that described the survey and the time required for
completion and informed them that a snack would be provided as compensation
for their time, that all responses would be anonymous, and that the research
was approved of by their employer and the institutional review board of the
University of Nebraska Medical Center. Participation rates among the 6 firms
varied from 50% to 100%. A total of 373 employees received letters of invitation
and 304 completed the survey for an overall participation rate of 82%.
To test the hypothesis that telemarketers have a higher prevalence of
voice problems than the general population, we also surveyed a convenience
sample of 187 community college students similar to the telemarketers in age
range, education level, and smoking status. The students were recruited in
the commons areas of the 3 separate branches of a local community college
in December 2000 and January 2001. Students read a similar letter of invitation
and also received a compensatory snack for completing the survey. The student
"control survey" was identical to the 57-item voice survey except that the
16 questions regarding the work environment were excluded.
The voice survey was developed from a review of the literature regarding
occupational voice disorders and included recommendations from otolaryngologists,
a speech and language pathologist, and the human resource and managerial professionals
from the surveyed firms. The survey consisted of the following:
- 16 questions regarding the employee's telemarketing
work history and environment
- 7 questions concerning respiratory health, medication
use, hearing ability, smoking, acid reflux, and caffeinated vs noncaffeinated
beverage intake
- 3 questions concerning amount, speed, and volume
of social speech
- 2 questions concerning general activity level and
participation in vocally demanding activities
- 1 question regarding previous vocal hygiene education
- 14 yes/no response questions concerning the current
presence of various symptoms of vocal attrition (participants were instructed
that these symptoms do not include sore throat or laryngitis associated with
a common cold)
- 2 items to rank the quality of their voice at the
beginning and end of a shift
- 2 questions regarding the employee's characterization
of and feelings about the presence of any symptoms of vocal attrition
- 2 questions regarding the impact of any symptoms
on the employee's work and social life
- 1 question regarding the relationship between season
of the year and presence of symptoms
- 2 questions regarding previous treatment for symptoms
of a voice problem
- 5 demographic questions
STATISTICAL ANALYSES
All raw data were entered into an Access database (Microsoft Inc, Redmond,
Wash) to determine descriptive statistics. Analyses were performed using SAS
software (SAS Institute Inc, Cary, NC). The end points of interest in comparing
the telemarketers with the community college students are the prevalences
of reporting 1 or more symptoms of vocal attrition and decreased social interaction
due to symptoms. The end point of interest concerning the telemarketing group
is the prevalence of impaired job performance due to symptoms of vocal attrition.
The Fisher exact test and multiple logistic regression analysis were used
to examine the association of telemarketing with the 2 end points of reporting
1 or more symptoms of vocal attrition and interacting less with family and
friends. The Fisher exact test was also used to determine significant associations
between biological, vocational, and personality factors and impaired telemarketing
job performance due to symptoms of vocal attrition. All tests were 2-sided,
and P .05 was considered statistically significant.
RESULTS
The age, sex, race, education level, and smoking status of the telemarketers
and community college students are given in Table 1. The 2 groups are similar with respect to age and smoking
status. However, the telemarketing group has more women than the student group
(P = .007).
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Table 1. Demographic Factors of Telemarketers and Students*
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A total of 206 (68%) of the 304 telemarketers and 90 (48%) of the 187
community college students reported 1 or more symptoms of vocal attrition.
This increased prevalence of the 14 symptoms of vocal attrition in the telemarketers
is shown in Figure 1. Telemarketers
are significantly more likely than the students to experience 8 of the 14
symptoms (P<.01). Multiple logistic regression
analysis was used to find the odds of 1 or more symptoms of vocal attrition
due to telemarketing while adjusting for age, sex, and smoking status. In
this analysis, 4 observations were omitted owing to missing information. As
given in Table 2, telemarketers
are 2.1 times as likely to have 1 or more symptoms of vocal attrition than
the students after adjusting for age, sex, and smoking status (P<.001). Smoking and sex, independent of telemarketing, also show
a significant association with vocal attrition.
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Figure 1. Prevalence of symptoms: telemarketers
vs community college students.
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Table 2. Factors Associated With 1 or More Symptoms of Vocal Attrition
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Of 282 telemarketers 8 (3%) reported that their voice problems caused
them to interact less with family or friends, while 7 (4%) of the 187 community
college students reported the same. The Fisher exact test did not indicate
a significant association between telemarketing and interacting less with
family and friends. However, female sex (P = .04)
and each 1-year increase in age (P = .03) demonstrated
an increased odds of interacting less with others because of a voice problem
for both telemarketing and student participants. Women were 8.65 times (95%
confidence interval, 1.1-67.6) as likely as men to report interacting less
with family and friends because of a voice problem. Every 1-year increase
in age results in a 4% increase in the risk of reporting decreased social
interaction because of a voice problem.
Of the 304 voice participants, 94 (31%) responded that they had worked
while having a voice problem and that this problem affected their productivity.
These 94 participants were then asked to indicate whether 5 statements described
the effect of the voice problem on their work. The frequency in which the
5 statements were chosen is given below.
Table 3, Table 4, and Table 5
summarize the differences between the participants who reported that their
work was affected by the presence of symptoms and those whose work was not
affected. Table 3 reports the
association of demographic, vocational, and personality factors and work being
affected by symptoms of vocal attrition. Female sex is the only demographic
variable that is significantly associated with work being affected by symptoms.
Such vocational factors as years worked in telemarketing, length of the shift
worked, and hours worked per week are not significantly associated with reporting
that work is affected by a voice problem. Those who indicated that they frequently
experienced a stressful call and who described their work environment as dry
or cold were significantly more likely to have indicated that their work was
affected. Indicating a need to raise one's voice more than a few times each
shift because of noise is associated with work being affected (P = .051). The personality factors "I talk more than others" and "I
talk louder than others" are significantly associated with reporting that
work is affected by a voice problem.
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Table 3. Association of Demographic, Vocational, and Personality Factors
With Telemarketing Work Being Affected by Symptoms of Vocal Attrition*
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Table 4. Association of Biological Factors With Telemarketing Work
Being Affected by Symptoms of Vocal Attrition*
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Table 5. Factors Indicating the Severity of Symptoms for Those Whose
Work Is Affected*
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The biological factors investigated are given in Table 4. Reporting frequent colds, regularly clearing the throat,
experiencing a dry mouth and throat, and taking drying medications are significantly
associated with work being affected by symptoms. Those whose work is affected
tend to drink more beverages per shift than those whose work is not affected.
The association between having a dry mouth and throat and taking drying medications
is statistically significant (P = .002). Additional
significant biological factors for work performance being affected by symptoms
are inactivity, smoking, and regularly experiencing acid reflux or "heartburn."
Reporting "I don't participate in any other additional activities that might
stress my voice" is significantly associated with work performance not being
affected by symptoms.
The increased prevalence of the 14 symptoms of vocal attrition in telemarketers
whose work was affected compared with those whose work was not affected is
shown in Figure 2. Telemarketers
whose work was affected are significantly more likely to experience 12 of
the 14 symptoms than those whose work was not affected (P<.01). Table 5 reports
the greater effect of symptoms of vocal attrition on telemarketers whose work
was affected (n = 94) compared with those telemarketers with symptoms whose
work was not affected (n = 112). Those whose work was affected averaged 5.0
symptoms of vocal attrition; 78% desired instruction about caring for their
voices, 50% had missed work because of a voice problem, and 8% had interacted
less with family and friends owing to their voice problem. Sixty-nine percent
of those whose work was affected and 80% of those whose work was not affected
reported that their voices were normal at the beginning of their work shift.
By the end of the work shift, only 17% of those whose work was affected reported
that their voices were normal, while 36% of those whose work was not affected
considered their voices to be normal. Regarding whether a physician had been
seen because of a voice problem, there was no statistical difference between
those whose work was affected (14%) and those whose work was not (9%). Only
4 of the 304 telemarketers reported that they had seen a speech therapist
because of a voice problem, and only 1 of those 4 reported that their work
was affected by a voice problem.
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Figure 2. Prevalence of symptoms: telemarketers
whose work is affected vs those whose work is not affected.
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COMMENT
The health status of an individual or population is a result of the
interaction between behavior and lifestyle, heredity, environment, and medical
care.22 Our cross-sectional survey of voice
problems in telemarketers confirms the interaction between multiple factors
in determining vocal health. Voice is the primary work tool for one third
of those in industrialized societies, and previous studies have shown an association
between voice problems and vocation.3-11
Our study sought to evaluate the prevalence and risk factors for voice problems
among telemarketers.
As expected, we found a significant increase in the prevalence of symptoms
of vocal attrition in telemarketers compared with a control group of community
college students. The telemarketing group was twice as likely to have 1 or
more symptoms after adjusting for age, sex, and smoking status compared with
the student group. Regression analysis found female sex and smoking status
to be independent factors strongly associated with symptoms of vocal attrition.
The finding that female sex is independently associated with vocal attrition
is consistent with current research. In a cross-sectional study of 25 cadaveric
vocal folds, Butler et al23 found that women
have less hyaluronic acid in the first 15% of depth (most superficial) of
the lamina propria (subepithelial layer) compared with men. These authors
conclude that this decrease in hyaluronic acid among women may provide less
protection from vibratory trauma and overuse and may explain in part why women
have more voice-related trauma than men.
Impaired work productivity due to voice problems occurred in 31% of
the telemarketers surveyed. Impaired productivity was attributed to the communication
difficulties of needing to repeat what was said and having to force the voice
to be understood. These communication difficulties caused a decrease in call
frequency and diminished enthusiasm for selling the product. Unexpectedly,
within the telemarketing group, factors indicating workload were not significantly
associated with prevalence of symptoms and impaired productivity, while half
of the biological factors and 2 of 3 personality factors were significantly
associated with symptom prevalence.
A major limitation of our study is the reliance on self-report, which
is inherent in survey research. However, the number of people surveyed (N
= 560) and the high participation rate of 82% contribute to the validity of
the findings. An additional limitation is that the telemarketing group was
surveyed during the summer and early fall, while the student group was surveyed
during the winter. Consequently, the telemarketing group may have been influenced
by seasonal allergies, while the student group may have been influenced by
the dryness of central heating during a midwestern winter. A major strength
of our study is the comparison between 2 groups similar in age and smoking
status but differing in occupational vocal load. The advantage of this design
is that the role of occupational vocal load in causing voice problems can
be separated from other determinants of vocal health.
The clinical significance of these findings is that evaluation of occupational
voice disorders must encompass all of the determinants of health status, and
treatment must focus on modifiable biological, environmental, and personality
factors and not simply reduction of the occupational vocal load. Although
occupational voice disorders are a direct result of the repetitive collision
of the vocal folds, additional risk factors are present when symptoms of vocal
attrition affect work productivity and social interaction. Evaluation of occupational
voice disorders should also include consideration of intrinsic laryngeal pathological
conditions such as malignancy, vocal cord nodules and polyps, and laryngeal
papillomatosis. Modifiable biological factors that should be considered include
smoking status, chronic sinusitis and frequent upper respiratory tract infection,
gastroesophageal reflux disease, the use of drying medications, hydration,
and complaints of dry throat. Once the laryngeal pathological condition and
modifiable biological factors have been addressed, complete management of
occupational voice disorders should then consider vocational load, speech
habits that are related to personality, and general activity level.
Addressing voice problems and the resultant impaired productivity in
telemarketers will require education of employers and employees regarding
the multifactorial nature of occupational voice disorders. Initiating a multidisciplinary
treatment plan for patients with occupational voice disorders is facilitated
by use of an in-take form designed to efficiently gather information regarding
all behavioral, lifestyle, hereditary, environmental, and vocational risk
factors. Speech and language pathologists in our voice clinic address the
issues of workplace vocal load, vocal use patterns, vocal hygiene, and education.
AUTHOR INFORMATION
Accepted for publication October 26, 2001.
This study was presented as poster R0050 at the annual meeting of the
American Academy of Otolaryngology–Head and Neck Surgery Foundation/Association
for Research in Otolaryngology, Denver, Colo, September 10-11, 2001.
Corresponding author: Katherine Jones, MS, 984350 Nebraska Medical
Center, Omaha, NE 68198-4350 (e-mail: kjonesj{at}unmc.edu).
Reprints:
Frederic Ogren, MD, ENT Physicians, PC, 17030 Lakeside Hills Plaza, Suite
200, Omaha, NE 68130.
From the University of Nebraska Medical Center, Omaha (Mss Jones, Hock,
and Sullivan and Dr Sigmon); Tulane University School of Medicine, New Orleans,
La (Mr Nelson); and ENT Physicians, PC, Omaha (Dr Ogren).
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