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The Development and Validation of a Dysphagia-Specific Quality-of-Life Questionnaire for Patients With Head and Neck Cancer
The M. D. Anderson Dysphagia Inventory
Amy Y. Chen, MD, MPH;
Ralph Frankowski, PhD;
Julie Bishop-Leone, MA, CCC-SLP;
Tiffany Hebert, MCD, CCC-SLP;
Stacy Leyk, MA, CCC-SLP;
Jan Lewin, PhD;
Helmuth Goepfert, MD
Arch Otolaryngol Head Neck Surg. 2001;127:870-876.
ABSTRACT
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Objective To design a reliable and validated self-administered questionnaire whose
purpose is to assess dysphagia's effects on the quality of life (QOL) of patients
with head and neck cancer.
Design Cross-sectional survey study.
Methods Focus groups were convened for questionnaire development and design.
The M. D. Anderson Dysphagia Inventory (MDADI) included global, emotional,
functional, and physical subscales. One hundred consecutive adult patients
with a neoplasm of the upper aerodigestive tract who underwent evaluation
by our Speech Pathology team completed the MDADI and the Medical Outcomes
Study 36-Item Short Form Health Survey (SF-36). Speech pathologists completed
the Performance Status Scale for each patient. Validity and reliability properties
were calculated. Analysis of variance was used to assess how well the MDADI
discriminated between groups of patients.
Results The internal consistency reliability of the MDADI was calculated using
the Cronbach  coefficient. The Cronbach coefficients of the
MDADI subscales ranged from 0.85 to 0.93. Test-retest reliability coefficients
of the subscales ranged from 0.69 to 0.88. Spearman correlation coefficients
between the MDADI subscales and the SF-36 subscales demonstrated construct
validity. Patients with primary tumors of the oral cavity and oropharynx had
significantly greater swallowing disability with an adverse impact on their
QOL compared with patients with primary tumors of the larynx and hypopharynx
(P<.001). Patients with a malignant lesion also
had significantly greater disability than patients with a benign lesion (P<.001).
Conclusions The MDADI is the first validated and reliable self-administered questionnaire
designed specifically for evaluating the impact of dysphagia on the QOL of
patients with head and neck cancer. Standardized questionnaires that measure
patients' QOL offer a means for demonstrating treatment impact and improving
medical care. The development and validation of the MDADI and its use in prospective
clinical trials allow for better understanding of the impact of treatment
of head and neck cancer on swallowing and of swallowing difficulty on patients'
QOL.
INTRODUCTION
OROPHARYNGEAL dysphagia is defined as difficulty in swallowing because
of structural or movement abnormalities involving the oral cavity, oropharynx,
velopharynx, hypopharynx, larynx, and upper esophageal sphincter. Patients
with cancer of the head and neck have signs and symptoms of swallowing problems
because the primary neoplasm affects the organ of swallowing and/or because
the treatment itself affects swallowing. Assessment of dysphagia by means
of modified barium swallows or cinefluoroscopy is valuable in determining
the extent of mechanical disability, but there are no such tools to address
the impact of dysphagia on quality of life (QOL). In addition, although treated
patients may be cancer free, 5-year survival rates or disease-free intervals
do not measure the toll of treatment on their ability to swallow. This patient-based
outcome may be measured by a valid and reliable questionnaire, such as the
M. D. Anderson Dysphagia Inventory (MDADI).
The MDADI can be used to assess how patients view the outcome of their
swallowing ability as a result of treatment and how this swallowing dysfunction
affects their QOL. For this assessment to be valid and reliable, the scale
used to assess the patients' views and perceptions must be developed in a
psychometrically rigorous fashion. The aim of this project is to design a
reliable and validated self-administered questionnaire that can be used to
determine the effects of dysphagia (swallowing disability) on the QOL of patients
with head and neck cancer.
PATIENTS AND METHODS
The use of focus groups facilitated questionnaire development and design.
The initial focus group consisted of faculty (H.G.), fellows (A.Y.C.), and
speech pathologists (J.B.-L., T.H., S.L., and J.L.) from the University of
Texas M. D. Anderson Cancer Center (UTMDACC), Houston. This initial group
formulated the basic content of the questions to be included in the MDADI
and was indispensable in the development of the MDADI and the establishment
of content or face validity.
However, few, if any, of the individuals in this first focus group have
experienced dysphagia themselves, except in short duration. The expected value
(or utility) of a given health state may be considered quite differently by
healthy subjects and subjects with disease, or by patients before and after
a disease is diagnosed. Thus, additional focus groups consisting of head and
neck cancer patients with dysphagia were formed. In these groups, patients
with dysphagia were asked to complete the initial version of the MDADI and
to share their life experiences regarding dysphagia. Aspects of their life
that were particularly difficult or troublesome to them were discussed and
elaborated. Four such focus groups of 4 to 8 patients each were convened.
Specific comments regarding wording of the questionnaire items were considered
and incorporated into the final version of the MDADI (Figure 1).
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The M. D. Anderson Dysphagia Inventory. E indicates emotional subscale;
F, functional subscale; and P, physical subscale. The first item constitutes
the global subscale. Scoring is explained in the "Scoring of the MDADI" subsection
of the "Patients and Methods" section.
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Patients eligible for the study were English-speaking adults with a
neoplasm of the upper aerodigestive tract who were undergoing evaluation by
UTMDACC Speech Pathology team. One hundred consecutive patients were included
in this study. Each patient completed the MDADI and the Medical Outcomes Study
36-Item Short Form Health Survey (SF-36), a generic health status measure.1 Twenty-nine patients completed the MDADI 2 weeks after
initial enrollment for test-retest reliability (reproducibility). Speech pathologists
(J.B.-L., T.H., S.L., and J.L.) completed the Performance Status Scale (PSS)
by List et al.2
Chart abstraction was performed to identify the age and sex of the patient,
site and stage of the initial primary tumor of the head and neck, time elapsed
since completion of the last treatment, type of treatment, and pathological
findings.
The data were then entered into a worksheet (Excel 97; Microsoft Corp,
Redmond, Wash). Analysis was performed using commercially available statistical
software packages (SAS, Version 6.12; SAS Institute, Cary, NC; and Minitab,
Version 12.2; Minitab Inc, State College, Pa).
RELIABILITY
Test-retest and internal consistency reliability were measured in this
study. Test-retest reliability was evaluated by administering the questionnaire
at the time of enrollment and 2 weeks thereafter. Aday3
suggests a minimum acceptable test-retest correlation of 0.7 for group-level
comparison and 0.9 for individual comparison. Internal consistency reliability
is useful in the construction of new scales or questionnaires and measures
the inconsistency or nonequivalence of different questions intended to measure
the same concept. Three main procedures for assessing the intercorrelation
among items are the corrected item-total, split-half, and reliability
coefficients. The internal consistency reliability measure calculated in this
study was the Cronbach coefficient. In most applied studies, the lowest
acceptable level of internal consistency reliability is 0.7 for group level
and 0.9 or higher for individual analysis.4
Values lower than 0.7 suggest that some items in the scale do not capture
the patient's attitude in the same manner as other items. Items contained
within a scale that have high correlations with the total contribute to the
scale's overall reliability and are more representative of scale content than
items with low item-total correlations. Individual-level analysis is used
for case-by-case assessment.
VALIDITY
The types of validity analyzed in this study were content, criterion,
and construct. Content validity was ensured by using a focus group of experts
and focus groups of patients and their family members. Criterion or concurrent
validity examines the strength of association of the new survey measure with
what is deemed to be an accurate measure of the same concept. The PSS is a
clinician-rated instrument consisting of 3 questions regarding normalcy of
diet, understandability of speech, and eating in public. Thus, it served as
the gold standard. We established construct validity by correlating item and
subscale scores with related constructs from other health status instruments
administered simultaneously with the MDADI. The SF-365
was used to test convergent and discriminative validity of the MDADI. A strong
correlation was defined to be 0.60 or greater; moderate to substantial, 0.40
to 0.60; and weak, less than 0.40.6
As a further demonstration of construct validity, the MDADI score was
expected to discriminate between groups of subjects, ie, scores on the MDADI
should differ when patients are grouped by severity (such as the site of the
tumor, pathological findings, and time elapsed since last treatment). These
between-group differences in MDADI scores were analyzed by analysis of variance.
Recurrent cancers were not included in the analysis.
SCORING OF THE MDADI
The complete MDADI is depicted in Figure
1. The global assessment consisted of a single question that asked
how the individual's swallowing difficulty affected overall daily routine.
This question is a general, overall assessment of QOL that has been affected
by swallowing difficulty. The emotional subscale of the MDADI consisted of
statements representing the individual's affective responses to the swallowing
disorder. The functional subscale attempted to capture the impact of the individual's
swallowing problem on daily activities. Items of the physical subscale represented
self-perceptions of swallowing difficulty. Five possible responses to the
items on the MDADI were printed for each item (strongly agree, agree, no opinion,
disagree, and strongly disagree) and scored on a scale of 1 to 5. One item
on the emotional subscale (I do not feel self-conscious when I eat) and another
on the functional subscale (I feel free to go out to eat with my friends,
neighbors, and relatives) were scored as 5 points for strongly agree and 1
point for strongly disagree. All other items were scored as 1 point for strongly
agree and 5 points for strongly disagree. The first question (global subscale)
was scored individually. All other questions regarding each aspect (emotional,
functional, and physical) of dysphagia were summed, and a mean score was then
calculated. This mean score was multiplied by 20 to obtain a score, with a
range of 0 (extremely low functioning) to 100 (high functioning). Thus, a
higher MDADI score represented better day-to-day functioning and better QOL.
RESULTS
PATIENT CHARACTERISTICS
The final sample consisted of 100 patients with characteristics as outlined
in Table 1. Mean (SD) age was
58 (10) years, with a range of 21 to 80 years. Most patients (70%) had advanced-stage
or recurrent cancer. For the 75 patients who received treatment, the mean
(SD) time since last treatment was 22 (47) months, with a range of 0.3 to
324 months. The distributions of the subscale scores are depicted in Table 2.
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Table 1. Characteristics of 100 Patients With Head and Neck Cancer
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Table 2. Distribution of MDADI Subscale Scores*
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RELIABILITY
The overall Cronbach coefficient for the questionnaire was 0.96.
The MDADI Cronbach of 0.96 exceeds the minimum acceptable value and
suggests that each item of the MDADI addresses the same concept. The subscales
also had acceptable internal consistency, as seen in Table 3. The test-retest reliability correlations of MDADI and the
subscales also exceeded the minimum acceptable correlation (global, 0.69;
emotional, 0.88; functional, 0.88; and physical, 0.86).
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Table 3. Test-Retest and Internal Consistency Reliability for MDADI
Subscales*
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CRITERION VALIDITY
Criterion or concurrent validity establishes that the new survey instrument
accurately reflects the attitudes of a previously used gold standard. In the
development of the MDADI, the PSS was used as the gold standard. Spearman
correlation coefficients were calculated. The global MDADI question had moderate
correlation with the questions on the PSS related to diet and eating in public
(0.53 and 0.47, respectively), as did the emotional (0.55 and 0.54, respectively)
and physical (0.59 and 0.53, respectively) subscales. The functional subscale
had moderately high correlation with the PSS (0.61 and 0.60 subscales). These
results demonstrate an acceptable level of correlation, thus establishing
that the MDADI and the PSS (eating in public subscale) measure psychosocial
aspects of swallowing (criterion validity).
CONSTRUCT VALIDITY
Correlations between the subscales of the MDADI and the subscales of
the SF-36 were calculated by using the Spearman correlation coefficient. The
8 domains of the SF-36 are physical functioning, role-physical, bodily pain,
general health, vitality, social functioning, role-emotional, and mental health.
The results are summarized in Table 4.
Correlation between the physical subscale of the MDADI and the physical functioning
subscale of the SF-36 was expected and demonstrated (0.40). Divergent validity
with the emotional (0.36) and functional (0.31) subscales was also expected.
Items of the role-physical domain of the SF-36 attempt to delineate the extent
of problems with work or other daily activities as a result of physical health.
The correlation with the MDADI physical subscale (0.39) was slightly less
than 0.40, but suggests some correlation. Divergent validity with MDADI emotional
(0.33) and functional (0.37) subscales was expected. Bodily pain was not measured
in the MDADI emotional, functional, and physical subscales; thus, all correlation
coefficients (0.23, 0.24, and 0.26, respectively) reflected divergence. General
health also was not measured in any of these MDADI subscales, and divergence
was evident in the correlation results (0.33, 0.28, and 0.32).
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Table 4. Construct Validity of MDADI and SF-36 Subscales*
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Because eating is one of the most common ways social beings interact,
significant correlations between vitality and the 3 MDADI subscales mentioned
(emotional, functional, and physical) were expected and observed (0.50, 0.45,
and 0.52). The vitality domain measures individual pep and energy. The social
functioning domain of the SF-36 measures the interference to social activities
as a result of physical or emotional problems. Correlations between social
functioning and these 3 MDADI subscales were also significant (0.50, 0.45,
and 0.51). The role-emotional domain of the SF-36 measures the extent to which
emotional problems interfere with work or other daily activities. Correlations
between the role-emotional domain and the MDADI emotional, functional, and
physical subscales were significant (0.40, 0.42, and 0.43, respectively).
Mental health was not measured in any of these MDADI subscales; thus, divergence
was evident in the correlation results (0.38, 0.32, and 0.37).
The global subscale of the MDADI consisted of only 1 question. This
question had convergent validity only when correlated with the social functioning
domain of the SF-36 (0.44), thus reflecting the wording of the question (Figure 1).
The Physical Components Score of the SF-36 is a compilation of the first
3 domains of the SF-36 (physical functioning, role-physical, and bodily pain).
The Mental Components Score is a summary score of the social functioning,
role-emotional, and mental health domains of the SF-36. The primary aim of
the MDADI is to measure psychosocial aspects of dysphagia, thus the significant
correlations of the Mental Components Score with all subscales of the MDADI
(0.44, 0.54, 0.51, and 0.54) were expected and observed.
KNOWN-GROUPS VALIDITY ANALYSIS
As the final measure of validity, the MDADI was able to detect differences
in groups of patients with head and neck cancer who were expected to be functioning
at different levels. The significant differences were detected when the patients
were grouped according to site and pathological features of the primary head
and neck tumor and the time elapsed since the last treatment of the primary
head and neck tumor (Table 5, Table 6, and Table 7).
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Table 5. Site and MDADI Subscale Scores*
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Table 6. Pathological Findings and MDADI Subscale Scores*
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Table 7. Time Elapsed Since Completion of Treatment and MDADI Subscale
Scores*
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The site of initial primary head and neck tumor was significantly associated
with the global assessment of swallowing-related QOL (P<.001) and with the remaining 3 subscales (P<.001
for all). Patients with primary tumors of the oral cavity and oropharynx had
significantly greater swallowing disability that caused an adverse impact
on their QOL. Patients with a malignant neoplasm also had significantly greater
swallowing disability as measured by the global assessment (P = .005) and emotional (P = .001), functional
(P = .001), and physical (P<.001)
subscales. The time elapsed since completion of treatment significantly affected
swallowing-related QOL as measured by the global assessment (P = .01). With longer time elapsed since completion of treatment, the
individual reported better swallowing function and overall QOL.
COMMENT
Most studies have provided physiological assessment of oral and pharyngeal
swallowing function.7-10
Valid and reliable QOL measurements may help to fill many voids in dysphagia
assessment. Such questionnaires can assess how variations in treatment affect
swallowing and how swallowing difficulty affects QOL. These scales can also
systematically document the effectiveness of a given treatment in terms of
physiological and QOL outcomes. Once data are gained on how QOL varies by
treatment as assessed by a dysphagia-specific tool and generic health measures,
the information can then be used to facilitate decision making by patients
and physicians. This information may also be used to monitor the longitudinal
course of individual patients' outcomes.
Functional status refers to the ability to
perform daily activities, and disease-specific functional
status refers to the impact of a given disease on particular functional
aspects that are affected by the disease. Although several validated instruments
have been designed to assess functional status in patients with head and neck
cancer,2, 11-15
at present, no disease-specific instrument exists for evaluating dysphagia
in the population with head and neck cancer.
The PSS2 is one of the few instruments
with items that measure how dysphagia affects one's performance status. However,
it is not self-administered, and it lacks detailed questions pertaining to
the psychosocial and emotional impact of dysphagia on patients' QOL.
McHorney and Rosenbek16 have begun development
of the SWAL-QOL (swallowing–quality-of-life instrument), a comprehensive
measure of QOL and quality of care that is specific to neurogenic oropharyngeal
dysphagia. This instrument is designed to represent the neurologic patient's
perspective in measuring QOL attributable to dysphagia. At present, it is
undergoing validity and reliability analysis.
The MDADI consists of the global, emotional, functional, and physical
subscales. Four subscales were developed to tap the different effects of dysphagia
on QOL. The global assessment question is a simple way of determining an overall
assessment. The values obtained in the global, emotional, functional, and
physical subscales of the MDADI exceed the minimum level for group-level comparison.
This suggests that the questions within the scale are consistently assessing
the same issues. The value for the emotional subscale may be slightly lower
than that for the other subscales because of the difficulty of reporting and
describing emotional issues. However, the Cronbach coefficient for
the emotional subscale is considered acceptable.
Test-retest reliability was also calculated in this project. In general,
minimum test-retest reliabilities of 0.70 are acceptable for group-level comparison.3 The values for the emotional, functional, and physical
subscales are thus acceptable for use in group-level comparison. Generally,
a higher level of test-retest reliability is necessary for individual-level
comparison, especially if the questionnaire is to be used to make clinical
judgments regarding treatment or outcomes on a case-by-case basis. The global
assessment had the lowest test-retest reliability score, possibly because
it consists of only 1 question. The other subscales had multiple questions
relating to the same domain.
Criterion validity was established by correlation using the PSS. The
correlations were sufficient to demonstrate that the MDADI measures similar
attributes as does the PSS. The correlation of the emotional subscale of the
MDADI with the PSS was lower than that of the other subscales of the MDADI.
A possible explanation for this lower correlation coefficient is that the
PSS is limited in its ability to assess emotional aspects of swallowing. The
PSS, in its original form, has 2 questions regarding swallowing and 1 question
regarding speech. The 2 swallowing questions concern normalcy of diet and
eating in public.2 The normalcy of diet subscale
assesses the degree to which a patient is able to eat a normal diet. The eating
in public subscale assesses the degree to which the patient eats in the presence
of others. Both questions assess more of the functional than the emotional
aspect of swallowing. This may explain the higher correlations with the physical
and functional subscales of the MDADI, compared with the emotional subscale.
If a good criterion already exists to assess psychosocial aspects of
swallowing, why develop a new one? The purpose of developing the MDADI is
not to eliminate the previously developed scale but to supplement it. One
way the MDADI supplements the PSS is by measuring how dysphagia affects one's
psychosocial and emotional well-being. In addition, the information obtained
with the MDADI is from the patients. The PSS is not self-administered but
is completed by a health care provider. The PSS asks 2 questions regarding
swallowing. The MDADI's 20 questions capture more completely and effectively
opinions and perspectives on the impact of dysphagia on QOL.
The SF-36 was used to establish validity in this study.1, 5
The SF-36 is a multi-item scale measuring the domains of physical functioning,
role-physical (role limitations due to physical health problems), bodily pain,
general health, vitality (energy/fatigue), social functioning, role-emotional
(role limitations due to emotional problems), and mental health (psychological
distress and well-being).5
The correlation between the physical functioning domain and the physical
subscale of the MDADI was expected because both address physical functioning.
Attempts were not made to measure bodily pain, general health, or mental health
with the MDADI, and thus no correlation of these SF-36 domains with the MDADI
subscales was expected. Eating is a social event for many humans, and thus
one may surmise that an individual with a good energy level and social functioning
would enjoy eating. On the contrary, one with a decreased energy level and
lower social functioning may be ashamed, embarrassed, unmotivated, or unwilling
to eat. Thus, the correlations with vitality, social functioning, and role-emotional
domains of the SF-36 and the MDADI subscales are expected.
The Physical Components Score is a compilation of the physical functioning,
role-physical, and bodily pain domains, and measures physical health status.
The Mental Components Score is a summary score of the social functioning,
role-emotional, and mental health domains, and measures emotional health status.
Because the primary aim of the MDADI is to assess psychosocial aspects of
dysphagia, it is not surprising that moderate correlations are evident with
each of MDADI's subscales and the Mental Components Score, but that no correlation
is evident with the Physical Components Score.
As a final measure of validity, the MDADI is able to detect differences
in groups of patients with head and neck cancer who were expected to be functioning
at different levels. The significant differences were detected when the patients
were grouped according to site of, pathological findings of, and time elapsed
since last treatment of the primary head and neck tumor. First, one would
expect a lesion in the oral cavity or oropharynx to cause more swallowing
difficulty. Indeed, when the head and neck cancer patients were grouped by
tumor location (oral cavity or oropharynx and hypopharynx or larynx), significant
decreases in global, emotional, functional, and physical aspects of dysphagia
were evident as measured by the MDADI.
Second, diagnosis of a malignant neoplasm would certainly affect one's
daily activities and health-related QOL. Indeed, global, emotional, functional,
and physical subscale scores were significantly lower among patients with
a malignant neoplasm compared with patients with a benign lesion in the head
and neck.
Third, one assumes that the further one is from treatment, the more
adept one is at adjusting to deficits caused by the tumor and/or treatment.
In this patient population, the longer the interval between completion of
treatment and assessment by the MDADI, the higher the global score, thus reflecting
a higher QOL and functional status as related to swallowing. Survival bias
may play a role in the association between time elapsed since last treatment
and higher MDADI global scores.
The cross-sectional study design in this project lends itself to selection
bias. The study population is selected from a tertiary care center; consequently,
the patients may not be fully representative of the total population of patients
with head and neck cancer. Furthermore, the study participants are selected
from a particular clinic in the tertiary care center. The Speech Pathology
clinic was selected because patients with swallowing difficulty are most likely
referred to this clinic for assessment and evaluation. Thus, the largest number
of patients with swallowing difficulty can be captured by targeting this clinic.
However, other patients with swallowing difficulty may not present to the
UTMDACC. Thus, those patients would not be offered an opportunity to participate
in this study, thereby introducing noncoverage bias. Nonresponse bias did
not play a major role in this project, because most patients (>95%) participated
voluntarily. Because this instrument was developed in a study population consisting
of head and neck cancer patients in a tertiary care center, caution is needed
in its generalizability to other patient populations with dysphagia.
CONCLUSIONS
Head and neck cancer and its treatment can adversely affect a patient's
QOL ability to eat. Disease-free survival, overall survival, and tumor response
rates have been the traditional outcome measures of treatment efficacy. Quality of life describes nontraditional outcome measures
of functional status and psychosocial well-being. Two general measures (general
and disease-specific) are used in QOL analysis. Disease-specific instruments
are designed to assess specific diagnostic groups or patient populations.
These measures are more responsive to changes in patient status over time.
The purpose of this project was to design a disease-specific instrument. The
MDADI is designed to be a valid and reliable instrument for evaluating QOL
issues associated with dysphagia.
To our knowledge, the MDADI is the first validated and reliable self-administered
questionnaire designed specifically for evaluating the impact of dysphagia
on the QOL of head and neck cancer patients. Standardized questionnaires measuring
patients' QOL offer a means for demonstrating treatment impact and for improving
medical care. Quality-of-life assessment is an important part of any clinical
trial that compares different treatment modalities. The development of the
MDADI and its use in prospective clinical trials will allow for better understanding
of the impact of treatment of head and neck cancer on swallowing and of swallowing
difficulty on patients' QOL.
AUTHOR INFORMATION
Accepted for publication November 14, 2000.
Presented at the annual meeting of the American Head and Neck Society,
Fifth International Conference on Head and Neck Cancer, San Francisco, Calif,
July 30, 2000; and winner of Scholarship Award, American Head and Neck Society,
2000.
Corresponding author: Helmuth Goepfert, MD, University of Texas M.
D. Anderson Cancer Center, 1515 Holcombe Blvd, Campus Box 441, Houston, TX
77030.
From the Department of Head and Neck Surgery, University of Texas M.
D. Anderson Cancer Center (Drs Chen, Lewin, and Goepfert and Mss Bishop-Leone,
Hebert, and Leyk), and the Department of Biometry, University of Texas School
of Public Health (Dr Frankowski), Houston.
REFERENCES
| |
1. Ware JE Jr, Sherbourne CD. The MOS 36-Item Short Form Health Survey (SF-36), I: conceptual framework
and item selection. Med Care. 1992;30:473-483.
WEB OF SCIENCE
| PUBMED
2. List MA, Ritter-Sterr C, Lansky SB. A performance status scale for head and neck cancer patients. Cancer. 1990;66:564-569.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
3. Aday L. Designing and Conducting Health Surveys. 2nd ed. San Francisco, Calif: Jossey-Bass/Pfeiffer; 1996.
4. Nunnally JC, Bernstein IH. Psychometric Theory. 3rd ed. New York, NY: McGraw-Hill Co; 1994.
5. Ware JE. SF-36 Health Survey: Manual and Interpretation Guide. Boston, Mass: Nimrod Press; 1993.
6. McHorney CA, Ware JE Jr, Lu JF, Sherbourne CD. The MOS 36-Item Short Form Health Survey III: tests of data quality,
scaling assumptions, and reliability across diverse patient groups. Med Care. 1994;32:40-66.
WEB OF SCIENCE
| PUBMED
7. Schliephake H, Schmelzeisen R, Schonweiler R, Schneller T, Altenbernd C. Speech, deglutition and life quality after intraoral tumour resection:
a prospective study. Int J Oral Maxillofac Surg. 1998;27:99-105.
WEB OF SCIENCE
| PUBMED
8. Teichgraeber J, Bowman J, Goepfert H. New test series for the functional evaluation of oral cavity cancer. Head Neck Surg. 1985;8:9-20.
WEB OF SCIENCE
| PUBMED
9. Murry T, Madasu R, Martin A, Robbins KT. Acute and chronic changes in swallowing and quality of life following
intraarterial chemoradiation for organ preservation in patients with advanced
head and neck cancer. Head Neck. 1998;20:31-37.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
10. Logemann JA, Pauloski BR, Rademaker AW, Colangelo LA. Speech and swallowing rehabilitation for head and neck cancer patients. Oncology. 1997;11:651-664.
PUBMED
11. Cella DF, Tulsky DS, Gray G, et al. The Functional Assessment of Cancer Therapy Scale: development and
validation of the general measure. J Clin Oncol. 1993;11:570-579.
FREE FULL TEXT
12. Hassan SJ, Weymuller EA Jr. Assessment of quality of life in head and neck cancer patients. Head Neck. 1993;15:485-496.
WEB OF SCIENCE
| PUBMED
13. Bjordal K, Kassa S. Psychometric validation of the EORTC Core Quality of Life Questionnaire:
a 30-item version and a diagnosis-specific module for head and neck cancer
patients. Acta Oncol. 1992;31:311-321.
WEB OF SCIENCE
| PUBMED
14. Morton RP, Witterick IJ. Rationale and development of a quality-of-life instrument for head-and-neck
cancer patients. Am J Otolaryngol. 1995;16:284-293.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
15. Terrell JE, Nanavati KA, Esclamado RM, et al. Head and neck cancer–specific quality of life: instrument validation. Arch Otolaryngol Head Neck Surg. 1997;123:1125-1132.
FREE FULL TEXT
16. McHorney CA, Rosenbek JC. Functional outcome assessment of adults with oropharyngeal dysphagia. Semin Speech Lang. 1998;19:235-246.
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