Keywords
M. D. Anderson dysphagia inventory - dysphagia - head and neck cancer - quality of
life
Introduction
Swallowing involves several steps in conveying a bolus from the oral cavity to the
stomach, including the oral stage, the pharyngeal stage, and the esophageal stage.[1] Dysphagia occurs due to structural or neuromotor abnormalities related to these
stages in the oral cavity, the oropharynx, the larynx, the hypopharynx, the velopharynx,
and the upper esophageal sphincter.[2]
[3] Dysphagia, which can lead to problems such as pneumonia, aspiration, malnutrition,
and even death, is a significant symptom in many neurological diseases such as stroke,
multiple sclerosis, Parkinson disease (PD), dementia, and head and neck cancer (HNC).[1]
[4] Furthermore, this disorder can lead to long-term social and functional limitations,
mood disorders such as anxiety and depression, nutritional deficiencies, and a decreased
quality of life (QOL).[5]
[6]
[7]
Head and neck cancer is a general term that encompasses cancer in the oral cavity,
the larynx, the pharynx, the salivary glands, the thyroid, the nasal sinuses, and
lymph nodes in the neck.[8] Dysphagia is a prevalent and critical condition in HNC patients, and various factors
may contribute to its presence, including the primary tumor site and anticancer treatments.
It can manifest before, during, and after radiotherapy.[9]
[10] Moreover, the clinical phenotypes of dysphagia (chewing difficulties, nasal regurgitation,
oral retention of food bolus, and choking) and its complications (malnutrition and
aspiration pneumonia) have a significant impact on the health and QOL of these patients.[8]
[10] The World Health Organization (WHO) defines QOL as “individuals' understanding of
their position in life within their culture and value systems concerning their expectations,
goals, concerns, and standards”[11]
[12]. To assess QOL in people with dysphagia, several questionnaires such as the Swallowing
Quality of Life (SWAL-QOL), Dysphagia Handicap Index (DHI), and MD Anderson Dysphagia
Inventory (MDADI) have been developed. The MDADI is specifically designed to assess
QOL in patients with HNC.[13] The MDADI was first developed in the USA in 2001 and has since been translated into
many other languages.[2]
[7]
[8]
[10] This tool is a widely used questionnaire for assessing patients' perspectives on
their swallowing ability, the impact of dysphagia on their QOL, and the efficacy of
dysphagia treatment.[2]
The MDADI was originally developed in English and requires modification for use in
other languages. Consequently, due to the lack of an available QOL questionnaire specifically
designed for HNC patients in Iran, our objective was to translate, culturally adapt,
and validate the MDADI in Persian. This process will render MDADI-P comprehensible
and allow clinicians in Iran to easily administer it. Therefore, conducting this research
is necessary and practical, as it can aid in the assessment of QOL in HNC patients
with dysphagia.
Materials and Methods
The present research was approved by the Human Participants' Ethics Committee (Reference
number: IR.USWR.REC.1399.033).
Participants and Data Collection
Participants and Data Collection
A cross-sectional study was conducted in three hospitals: Imam Hussein Hospital, Amir
Aˈlam Hospital, and Shohadaye Tajrish Hospital in Tehran, Iran, between April 2020
and August 2020. Seventy-five patients were selected based on the inclusion criteria.
Eligibility Criteria
The inclusion criteria were as follows: (1) age ≥ 18 years old, (2) histologically
and pathologically confirmed HNC by a clinical oncology specialist, (3) diagnosed
dysphagia by the researcher using the Northwestern Dysphagia Patient Check Sheet,
and (4) willingness to participate in the study by signing informed consent.
The exclusion criteria were: (1) dysphagia due to other reasons and (2) impaired alertness.
Patient-Reported Outcome Instruments
Patient-Reported Outcome Instruments
MDADI
The MDADI is a psychometrically validated, self-administered, and reliable questionnaire
developed by Chen et al. It aims to assess the impact of dysphagia on the health-related
QOL in patients with HNC. It consists of 4 subdomains: global (1 question), emotional
(6 questions), functional (5 questions), and physical (8 questions).[2]
[13]
[14] The global question measures the impact of swallowing ability on day-to-day activities.
The emotional subdomain evaluates the affective reaction of HNC patients to swallowing
problems. The functional subdomain illustrates how the daily activities of the patient
are affected by the swallowing disorder, and the physical subdomain indicates the
perception of the patient of the swallowing disorder.[9]
[10]
[15]
The MDADI is scored on a 5-point Likert scale: 1. strongly agree; 2. agree;3. no opinion;
4. Disagree; and 5. firmly disagree. However, two items on the emotional and functional
subdomains (E7: “I do not feel self-conscious when I eat” and F2: “I feel free to
go out with my friends, neighbors, and relatives”) are reversely scored: 5. firmly
agree; 4. Agree; 3. no opinion; 2. Disagree; and 1. strongly disagree.[2] The global domain is scored separately, while the average scores of other items
in each subdomain are calculated. The average score is then multiplied by 20 to obtain
a final score ranging from 20 (poor functioning) to 100 (high functioning).[2]
[8]
The Short Form-36 (SF-36)
The SF-36 is a general questionnaire for evaluating health-related quality of life
(HRQOL).[14] It assesses eight subdomains and provides two summary scores (physical and mental).
The eight subdomains include physical functioning (PF), bodily pain (BP), role limitations
due to physical problems (RP), vitality (VT), general health perceptions (GH), role
limitations due to emotional problems (RE), social functioning (SF), and mental health
(MH). Higher scores indicate better HRQOL.[16] This tool was validated in Iran in 2005 by Montazeri et al.[17]
Top of Form
MDADI Translation Process
The MDADI translation process involves several steps that ensure accurate and culturally
adapted translations based on WHO guidelines. Each step is carefully executed to maintain
the integrity and quality of the translated questionnaire.[18]
Forward Translation
Initially, the author obtained permission from the creator. Then, the MDADI was translated
by a translator and a speech-language pathologist (SLP). The focus during this translation
was on conceptual accuracy rather than literal translation.
Expert Panel
In this step, two SLPs who specialized in dysphagia were selected to identify and
clarify any expressions or concepts within the translation. Their expertise ensured
the accuracy and relevance of the translated content.
Backtranslation
An independent translator (also an SLP), who was unfamiliar with the questionnaire,
performed a backtranslation of the translated version into English. This backtranslation
was sent to the creator for approval. Once approved, a pre-final Persian version of
the MDADI was obtained for subsequent pretesting and cognitive interviews.
Pretesting and Cognitive Interviewing
Before the final sampling, a pretest version of the MDADI was administered to 10 HNC
patients with dysphagia under experimental conditions. The patients provided their
feedback, comments, and suggestions regarding the inventory questions. Incorporating
the valuable input of the patients, the final version of the questionnaire was prepared
Final Version
The final version of the MDADI-P questionnaire was developed by diligently following
all the aforementioned steps. Subsequently, the questionnaire retrieval steps were
performed, ensuring content validity and data collection within the target population.
Statistical Analysis:
Ten SLPs experienced in managing dysphagia evaluated the content validity of the MDADI-P.
They assessed the relevance of items related to dysphagia, the quality of translation,
fluency, and understandability. The content validity index (CVI) was calculated based
on their scoring criteria.
Validity and reliability scores were calculated using IBM SPSS Statistics for Windows,
version 23 (IBM Corp., Armonk, NY, USA). To determine reliability, 32 patients were
reassessed using the MDADI-P questionnaire after 2 weeks. The interclass correlation
coefficient (ICC) was used to evaluate the test-retest reliability, with ICC values > 0.7
considered acceptable. Values > 0.8 and 0.9 were regarded as indicating good and excellent
reliability, respectively.[19] Pearson correlation coefficient was used to evaluate the correlations between continuous
variables, while Spearman rho was used for ordinal variables. The internal consistency
reliability of the combined MDADI score and each subdomain was assessed using Cronbach
alpha tests. An internal consistency reliability level of at least 0.7 was considered
acceptable.
Results
Sample Characteristics
Demographic data for the 75 patients (aged 20 to 88 years old) who participated in
the study are presented in [Table 1]. Most of the participants were male patients with an average age of 53 years old.
The most common tumor sites were the oral cavity and the larynx, and the majority
of patients received treatment through surgery and radiotherapy.
Table 1
Demographic and clinical characteristics (n = 75)
|
Variable
|
Category
|
N (%)
|
|
Gender
|
Male
Female
|
59 (78.7)
16 (21.3)
|
|
Age (years old)
|
Range
Median
Mean ± SD
|
20–88
57
53 ± 1.88
|
|
Site of lesion
|
Oral cavity
Pharynx
Larynx
Others
|
21 (28)
15 (20)
21 (28)
18 (24)
|
|
Treatments
|
Surgery
Radiotherapy
Chemotherapy
Surgery and radiotherapy
Radiotherapy and chemotherapy
Surgery and radiotherapy and chemotherapy
None
|
7 (9.3)
14 (18.7)
4 (5.3)
20 (26.7)
15 (20)
9 (12)
6 (8)
|
Content Validity
Ten SLPs scored most of the MDADI questions with a kappa coefficient ≥ 0.79, indicating
excellent content validity. Additionally, two questions of the MDADI-P achieved a
kappa coefficient of 0.66, demonstrating good content validity. Ultimately, we concluded
that the MDADI-P, with an S-CVI of 0.9, has excellent content validity ([Table 2]).
Table 2
Kappa coefficient score of the MDADI questions
|
QUESTION
|
Subscale
|
Kappa (CI)
|
Result
|
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
Global
Emotional
Functional
Physical
Emotional
Emotional
Physical
Emotional
Functional
Physical
Physical
Emotional
Physical
Functional
Functional
Physical
Physical
Emotional
Physical
Functional
|
1
0.9
0.66
0.79
0.79
1
1
0.79
0.79
1
1
0.9
0.9
1
0.9
1
1
1
0.79
0.66
|
Excellent
Excellent
Good
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Good
|
Reliability and Internal Consistency
The total Cronbach alpha obtained for the MDADI-P was 0.728. The test-retest reliability
for each subdomain of the MDADI-P (global, emotional, functional, and physical) ranged
from 0.56 to 0.912. Furthermore, the ICC of the test-retest reliability for the total
score of the MDADI-P was > 0.91 (0.81-0.95), which is considered appropriate ([Table 3]).
Table 3
Cronbach α coefficients and intra-class correlation (ICC) for the MDADI subscales
|
Standard deviation
|
ICC
|
95%CI
|
|
Global
Emotional
Functional
Physical
Total
|
13.8
10.22
12.57
8.34
7.90
|
0.56
0.84
0.91
0.85
0.91
|
0.42-0.73
0.681-0.924
0.82-0.95
0.7-0.92
0.81-0.91
|
Abbreviations: CI, confidence interval; ICC, intraclass correlation
Construct Validity
The correlations between the subdomains of the MDADI-P and the SF-36 subdomains were
measured using the Spearman correlation coefficient. The eight subdomains of the SF-36
are physical functioning, physical role, bodily pain, emotional role, social functioning,
vitality, and general health. The results are presented in [Table 4]. The total score of the SF-36 correlated with the total score of the MDADI-P (r = 0.42;
p < 0.05). The total score of the MDADI-P also showed a good correlation with the physical
and mental components of the SF-36 (0.456 and 0.349, respectively, p < 0.05). Correlations between the MDADI-P total score and other SF-36 subscales such
as physical functioning, vitality, bodily pain, general health, and mental health
were calculated (r = 0.292 to 0.467; p < 0.05). Additionally, the subscales of the MDADI-P demonstrated a good correlation
with the physical functioning and general health subscales of the SF-36 (r = 0.194
to 0.405 and 0.201 to 0.396, p < 0.05, respectively). However, the subscales of the MDADI-P showed a weak correlation
with the emotional role and physical role subdomains of the SF-36.
Table 4
Construct validity (convergent validity): Spearman correlation coefficients between
the subdomains of the MDADI and the subdomains of the SF-36
|
MDADI
SF-36
|
Global
|
Emotional
|
Functional
|
Physical
|
Total
|
|
Physical functioning
|
0.194
|
0.367*
|
0.327*
|
0.405*
|
0.467*
|
|
Social functioning
|
- 0.1
|
0.05
|
0.09
|
0.223
|
0.156
|
|
Physical role
|
0.02
|
- 0.105
|
- 0.04
|
0.08
|
- 0.028
|
|
Emotional role
|
0.43
|
- 0.145
|
0.07-
|
0.225
|
0.013
|
|
Mental health
|
0.112
|
0.267*
|
0.285*
|
0.142
|
0.292*
|
|
Vitality
|
0.233*
|
0.166
|
0.172
|
0.209
|
0.233*
|
|
Body pain
|
0.040
|
0.196
|
0.222
|
0.295*
|
0.304*
|
|
General health
|
0.201
|
0.396*
|
0.361*
|
0.319*
|
0.455*
|
|
Physical components
|
0.222
|
0.332*
|
0.327*
|
0.413*
|
0.456*
|
|
Mental components
|
0.179
|
0.206
|
0.250*
|
0.359*
|
0.349*
|
|
Total
|
0.186
|
0.268*
|
0.297*
|
0.433*
|
0.427*
|
* p < 0.05.
Discussion
We translated the MDADI into Persian and confirmed its validity and reliability. Seventy-five
patients who thoroughly answered all the questionnaires participated in the present
study; therefore, the feasibility can be considered reliable.
For other language versions (Dutch, Korean, Portuguese, Japanese, Chinese, and Swedish),
the total Cronbach α coefficients range from 0.81 to 0.95 (in Persian, it is 0.728).[7]
[10]
[14]
[20]
[21]
[22] The Cronbach α coefficient of the Persian version was 0.728, which is comparable
to the MDADI in other languages.
Regarding test-retest reliability, the ICC for the global subscale of MDADI-P was
0.56. The other language versions (Japanese, Korean, and Swedish) also showed low
scores for the ICC of the global subscale. This could be attributed to the fact that
the global subscale consists of a single item. The emotional subscale of other versions
(Dutch, Korean, Portuguese, Japanese, Chinese, and Swedish) demonstrated ICC values
ranging from 0.88 to 0.93, and the MDADI-P also exhibited a good level for this subscale
(ICC = 0.84). Moreover, the functional (ICC = 0.91) and physical (ICC = 0.85) subscales
of MDADI-P showed excellent and good levels, respectively. In comparison, the ICC
values for these subscales in other versions (Dutch, Korean, Portuguese, Japanese,
Chinese, and Swedish) ranged from 0.84 to 0.97 and from 0.84 to 0.96, respectively.
Overall, the total ICC for MDADI-P demonstrated an excellent level (ICC = 0.91), similar
to other language versions.[7]
[10]
[14]
[20]
[21]
[22]
Regarding construct validity, the correlation between the MDADI-P subdomains and the
SF-36 subdomains was reported. The correlation between the physical subdomains of
the MDADI-P and physical functioning in SF-36 was 0.405, which is consistent with
the original MDADI (r = 0.40). Similarly, the MDADI-P exhibited divergent validity
for the emotional (0.367) and functional (0.327) subdomains, as observed in the original
MDADI.[2]
The correlations of all subscales of the MDADI-P with the mental and physical subdomains
of SF-36 were weak to moderate, similar to the findings of the Swedish, Spanish, and
Brazilian versions.[7]
[9]
[14] The correlations between the subscales of MDADI-P and the physical components of
the SF-36 ranged from 0.222 to 0.413, while the correlations between the mental components
of the MDADI-P ranged from 0.179 to 0.359. Additionally, similar to the Spanish versions
of the MDADI, the correlations between the physical and mental subdomains of the SF-12
with the subscales of the MDADI were between 0.314 and 0.495, and 0.391 and 0.503,
respectively.[9]
After translation and cultural modification, the MDADI-P was validated. During this
process, it was important to ensure that the MDADI-P was understandable and easily
applicable for clinical experts. Our findings revealed that the MDADI-P has high content
validity and face validity, making it an easy and efficient method in clinical settings.
Furthermore, our results demonstrated strong test-retest reliability for the MDADI-P.
Analyzing the limitations of the present study, the data collection coincided with
the outbreak of the Covid-19 epidemic, resulting in a reduction of the sample size
from 100 patients to 75. Additionally, due to the limited sample size, it was not
possible to conduct factor analysis to examine construct validity. Therefore, conducting
research with a larger sample size would allow for the investigation of other psychometric
features of MDADI, such as factor analysis to assess construct validity.
Conclusion
The content validity, construct validity, reliability, and internal consistency outcomes
of our study support the validity of the MDADI-P. Therefore, it is a suitable method
for evaluating the QOL in Persian patients with HNC for both research and clinical
purposes.
