The feasibility and test–retest reliability of the Dutch Swal-Qol
adapted interview version for dysphagic patients
with communicative and/or cognitive problems
Jessie Lemmens•Gerrie J. J. W. Bours•
Martien Limburg•Anna J. H. M. Beurskens
Accepted: 11 May 2012/Published online: 30 May 2012
? The Author(s) 2012. This article is published with open access at Springerlink.com
tionnaire to an interview format suitable for dysphagic
patients with communicative and/or cognitive problems
and evaluation of the feasibility and test–retest reliability.
An observational study with two measurements
within a 2-week time period in a sample of 57 stroke
patients with dysphagia in a nursing home environment.
The interview version of the Swal-Qol was evaluated in the
total group and in subgroups of patients with and without
communicative and/or cognitive problems.
The constructed interview version was consid-
ered feasible from an expert’s and patient’s point of view.
The overall score and seven subscales of the Swal-Qol
showed an excellent test–retest reliability (k[0.75), and
two subscales were considered good (k[0.60).
This study showed that using a structured,
and at the same time flexible, interview format tailored to
the individual needs of stroke patients enhances the feasi-
bility and does not compromise the test–retest reliability.
The adaptation of the Dutch Swal-Qol ques-
Dysphagia ? Quality of life ? Swal-Qol
Test–retest reliability ? Feasibility ?
Health Related Quality of Life (HRQOL) scales are
patient-reported outcome measures for gaining information
about a patient’s own health situation [1, 2]. When
assessing patients with communicative and/or cognitive
problems, caution is needed when using traditional
HRQOL scales since difficulties in understanding or
answering may occur [3–5]. Several studies give recom-
mendations for adjustments for patient groups with com-
municative and cognitive problems [6–9]. McHorney et al.
 developed the Swal-Qol questionnaire to evaluate the
impact of dysphagia on quality of life and was shown to be
a reliable and valid tool for measuring quality of life in
outpatients [11–14]. However, the current self-report ver-
sion is not feasible for patients as half of them need
assistance in filling it out [11, 13, 15]. Therefore, the aim of
this study was to adapt the Swal-Qol questionnaire for
dysphagic stroke patients with and without communicative
and/or cognitive problems and evaluate its feasibility and
A cross-sectional, clinimetric study design was used
with two measurements in a 2-week time period in a
sample of dysphagic stroke patients in a nursing home
Materials and methods
The Swal-Qol consists of 44 items divided in 10 scales
regarding quality of life: (1) burden, (2) eating duration,
(3) eating desire, (4) food selection, (5) communication,
(6) fear, (7) mental health, (8) social functioning, (9)
fatigue and (10) sleep that could be rated on a 5-point
J. Lemmens (&) ? G. J. J. W. Bours ? M. Limburg ?
A. J. H. M. Beurskens
Zuyd University of Applied Sciences, Heerlen, The Netherlands
Qual Life Res (2013) 22:891–895
Likert scale. In addition, there are scales on symptom
frequency, nutrition intake (tube, consistency of food
and/or liquids), assistance with filling out, general health
and some demographics . We adapted the Dutch
translation of the Swal-Qol  into an interview version
by using a two-step response method with supportive
visual aids [6–9]. The adaptation process is described in
Stroke patients with dysphagia were recruited by speech
and language therapists (SLTs) responsible for dysphagia
treatment in nursing homes. Patients were eligible when
they were physically and mentally fit enough to participate.
Patients were excluded if they did not speak Dutch. The
SLTs gave eligible patients oral and written information
Box 1 Swal-Qol adaptations, from self-report to interview version
Purpose: enabling patients to portray their own perspective, instead of depending on proxy reports.
The interviews format was adjusted to the communicative capabilities of the patients by:
- using questions instead of statements [4-8],
- administrating scales and items in a flexible order,
- giving explanations or demonstrations of unclear items such as ‘clearing throat’ .
Step 1: developing a standardized interview format
Purpose: limiting item sampling errors.
The comprehension of items was enhanced by:
- using directive speech ,
- rephrasing items in which vague language or negative phrasing was used ,
- changing the recall time from ‘last month’ to ‘last week’ .
Step 2: simplifying instructions and items
Purpose: designing a suitable ordinal scale for patients for whom Likert scales are problematic [8, 18], by:
- creating a two step responds method (see example).
Step 3: revising the five-point Likert scale
Purpose: supporting verbal communication which benefits comprehension, focus and memory.
Different layout styles were designed:
- a) enlarged font, b) key words in bold/underlined, c) separate pages for each item,
d) separate response cards,
- vertical response cards for patients with a neglect or hemianopia .
Step 4: designing visual aids
Purpose: combining theoretical and practical insight and getting independent approval for practical use.
Five independent SLT’s with at least three years of experience with dysphagic stroke participated by:
- giving suggestions for tailoring the original Swal-Qol,
- confirming the suitability of the adapted interview, instructions, items and response scales.
Step 5: involvement of experts
Interviewer asks : ‘Is it difficult to deal with your swallowing problem?
Patient answers: ‘yes’, ‘no’ or comes up with a more specific answer for example: ‘depends on the day’ or ‘I
If yes: the interviewer nods and responds (in neutral tone while observing the patients reaction): ‘ah, it is’. Then
asks a second question: ‘Is it very difficult (1), remotely difficult (2) or a little bit difficult (3) for you?’
If no: the interviewer shakes his head and responds (in neutral tone while observing the patients reaction): ‘ah, it
is no problem for you’. Then asks a second question: ‘Is it never a problem (5) for you or occasionally (4)?’
In case a patient doesn’t know, the interviewer checks if the patient doesn’t recall or if the item is unclear and
then gives a suitable explanation.
If necessary the interviewer repeats every answer option separately or suggests to use a visual aid.
Dealing with my Swallowing Problem is very
Partly TrueA Little true
Almost never true
Not true at all
1 2 3 4 5
892Qual Life Res (2013) 22:891–895
and asked permission for the interviewers to approach
them. If patients were not able to give written consent,
permission was asked in the presence of family members.
If at 2-week follow-up patients did not recall giving con-
sent, it was asked for again.
Communicative problems as dysarthria and aphasia were
diagnosed by a SLT. Cognitive problems were defined as
neuropsychological symptoms following stroke and were
diagnosed by a psychologist. The severity of dysphagia
was determined by feeding status. Dysphagia was consid-
ered ‘severe’ when patients were fed by tube (with and
without oral intake), ‘moderate’ when there was oral intake
with adjusted consistency and ‘mild’ in the case of normal
oral intake with adaptive strategies.
Feasibility was defined as time to complete the interview,
use of visual aids, item comprehension and burden from an
observer’s and patient’s perspective. Burden was described
as to what extent the interview had been tiresome for the
patient. Regarding the patient’s perspective, two questions
on a three-point scale about comprehension and burden
Test–retest reliability was assessed by administrating two
identical Swal-Qol interviews with the same interviewer.
A 2-week time interval was considered enough time for
patients not to remember their previous answers.
The SLTs and psychologist diagnosis were derived from
the patients’ medical records to gather information on
communication and cognition. Two trained assessors, one
interviewer and one observer, conducted all the interviews.
All patients were asked whether they preferred to use
visual aids. The interviewer administered the Swal-Qol
interview and wrote down the answers given by the patient;
the observer reported the feasibility aspects. The use of
visual aids and explanations were standardized in the
second interview to guarantee that both interviews were
identical. Before the second interview, the assessors
checked whether no major changes had occurred in health
The Predictive Analytics Software (PASW, version 18)
program was used for data analyses. Patient characteristics
were reported in frequencies. Subgroups were formed based
on the presence of communicative and/or cognitive prob-
lems. Feasibility aspects were analyzed using descriptive
techniques (i.e., mean, standard deviation, frequencies).
Subscales with at least one incomplete answer were
excluded from test–retest analyses. The test–retest reli-
ability for each subscale and overall score was reported by
the weighted kappa and is considered good between 0.40
and 0.75 and excellent above 0.75 [16, 17]. To compare the
data with previous published studies, the Spearman’s rho
correlation coefficients and the intraclass correlation coef-
ficients (ICC) were calculated.
A total of 61 patients met the inclusion criteria of whom 57
gave their consent and 56 participated in both interviews.
Data were collected from April 2008–December 2009 in
seven nursing homes in the Netherlands. The average age
was 75.1 (±SD 12.1). Communication problems were
present in 30 (53 %) patients. The most frequent diagnosis
was aphasia or dysarthria (n = 24). Three patients had both
speech and language problems. Cognitive problems
occurred in 12 (21 %) patients and existed mostly of
amnesia or neglect (n = 11; Table 1). Two patients had
cognitive as well as communicative problems of whom one
only participated in the feasibility study.
The average time to complete the interviews was 41 (±SD
28) min, and 29 (37 %) patients needed 30 min or more.
There were no major differences between the group with
and without communicative and/or cognitive problems.
Visual aids were used in 30 (53 %) interviews. Half of
the patients without communicative or cognitive problems
(n = 8) preferred visual aids. Only the enlarged font
questionnaire (n = 11: 19 %) and separate response cards
(n = 18: 32 %) were applied, mainly to help patients
Difficulties in comprehension were reported in all 44
items of the Swal-Qol. In 12 (21 %) interviews, a pause
was needed, prolonging the administration time. Item
comprehension was easy to 45 (78 %) patients and difficult
to three (5 %) patients. The majority of the patients (82 %)
found the burden acceptable to low.
Qual Life Res (2013) 22:891–895 893
The average time between the two interviews was 14.9 (±
SD 3.1) days with a minimum of 7 and maximum of 24
(range = 17) days. Due to missing data, the sample size
per subscale varied between 48 and 56 patients (Table 2).
The weighted kappa was excellent (k[0.75) for the
overall score and seven subscales of the total group
(n = 56), the group with (n = 40) and without communi-
cative and/or cognitive problems (n = 16). It was good for
subscale ‘fear’ (k = 0.675/0.677/0.660) and ‘fatigue’
(k = 0.713/0.736/0.631). A further comparison between
communicative and cognitive problems showed that all
scales were excellent for the group with communicative
problems (n = 30). The sample size of the cognitive
impaired group was considered too small for analysis.
There were no major differences in test–retest reliability
between the use of the weighted kappa, the Spearman’s rho
and ICC (Table 2).
This study showed that using a structured, and at the same
time, flexible interview format tailored to the individual
needs of patients enhances the feasibility and does not
compromise the reliability for dysphagic stroke patients
with problems in communication and cognition.
In general, an interview format is more time-consuming
and requires more resources and training, but we demon-
strated that our adaptations led to a scale applicable within
Table 1 Sample characteristics (n = 57)
Male 24 (42)
Mean (SD) 75.1 (12.1)
Highest completed education
Elementary school22 (39)
High school16 (28)
Vocational training14 (25)
Severe: tube feeding 9 (16)
Moderate: oral intake with adjusted consistency25 (47)
Mild: normal oral intake with adaptive strategies
Communication and/or cognitive problemsa
Aphasia (language)12 (21)
Dysarthria (speech/voice) 12 (21)
Buccofacial/verbal apraxia (speech)5 (9)
Unclassified diagnosis (speech/language)
Cognitive problems (neuropsychological symptoms)a
Amnesia 6 (11)
None 16 (28)
aPatients can experience several problems in communication and/or
Table 2 Test–retest reliability
of the Swal-Qol subscales
(n = 56)
an is smaller than the group
size given at the top of each
Subscale (# items)
Subgroups (weighed kappa)
(n = 40)
(n = 16)
1 Burden (2) 560.849 0.854/0.850 0.862
2 Eating duration and desire
3 Dysphagia symptoms
540.940 0.934/0.941 0.960a
4 Food selection (2) 530.8230.834/0.818 0.836a
5 Communication (2)56 0.786 0.777/0.789 0.790
6 Fear (4)530.675 0.715/0.678
7 Mental health (5)550.898 0.877/0.8910.879
8 Social functioning (5)48 0.908 0.909/0.909
9 Fatigue and sleep (5)550.713 0.710/0.714 0.736
Overall score (44)48 0.9530.951/0.952
894 Qual Life Res (2013) 22:891–895
30 min in half of the cases. In comparison with previous Download full-text
Swal-Qol studies, with an average fill-out time between 14
and 30 min [11, 13, 15], time to complete our interviews
was much longer, mostly due to storytelling. However, the
length of the Swal-Qol interview is considered feasible,
since the majority of patients did not experience a heavy
burden and were satisfied with the time to complete and the
attention given by the interviewer.
Caution is needed when comparing our test–retest reli-
ability results with previous studies, since these studies
used the self-report version and excluded patients with
communicative and cognitive problems. Their population
was not limited to stroke, the sample sizes were small
(n\40), and most patients were not living in nursing
homes. Despite these differences, the results of our test–
retest reliability analysis are largely comparable with pre-
The absence of recent objective test results to estimate
the communicative and/or cognitive problems might have
influenced the group composition for the subgroup analy-
sis. Since our population consisted of a group of very frail
elderly, it was not considered ethical or practical to use
additional standardized tests; instead, the diagnosis was
derived from medical records. As group comparisons
showed no major differences between feasibility aspects
and test–retest reliability, it is not likely that this had a
large impact. Moreover, by allowing a group of patients to
participate who are usually excluded from research, we
believe our data are based upon a more representative
group of dysphagic stroke patients than reported thus far.
By tailoring measurement instruments for specific
patient groups without compromising the clinimetric
properties, data on subjective health status can be collected
in a larger and more representative population, which
benefits both research and clinical purposes. We think that
more specific instruments in different domains can be
adapted for use in this specific group of patients.
SLTs and nursing homes for their participation. We acknowledge our
assessors and especially L.H.J. Smeets for her contribution to this
The authors would like to thank all the patients,
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author(s) and the source are credited.
This article is distributed under the terms of the
1. Bullinger, M., Anderson, R., Cella, D., & Aaronson, N. K.
(1993). Developing and evaluating cross cultural instruments:
from minimum requirements to optimal models. Quality of Life
Research, 2(6), 451–459.
2. Williams, L.-S., et al. (1999). Measuring quality of life in a way
3. Price, C. I. M., Curless, R. H., & Rodgers, H. (1999). Can stroke
patients use visual analogue scales. Stroke, 30, 1357–1361.
4. Williams, L.-S., et al. (1999). Development of a stroke-specific
quality of life scale. Stroke, 30, 1362–1369.
5. Hilari, K., et al. (2003). Stroke and aphasia quality of life scale-39
(SAQOL-39), evaluation of acceptability, reliability, and validity.
Stroke, 34, 1944–1950.
6. Doesborgh, S., et al. (2003). Linguistic deficits in the acute phase
of stroke. Journal of Neurology, 250(8), 977–982.
7. Lloyd, V., Gatherer, A., & Kalsy, S. (2006). Conducting quali-
tative interview research with people with expressive language
difficulties. Qualitative Health Research, 16(10), 1386–1404.
8. Gerritsen, D. L., et al. (2007). Measurement of overall quality of
life in nursing homes through self-report: the role of cognitive
impairment. Quality of Life Research, 16, 1029–1037.
9. Dalemans, R., et al. (2010). Psychometric properties of the
Community Integration Questionnaire adjusted for people with
aphasia. Archives Physical and Medical Rehabilitation, 91(3),
10. McHorney, C. A., et al. (2000). The SWAL-QOL outcomes tool
for oropharyngeal dysphagia in adults: I. Conceptual foundation
and item development. Dysphagia, 15, 115–121.
11. Khaldoun, E., Woisard, V., & Verin, E. (2009). Validation in
French of the SWAL-QOL scale in patients with oropharyngeal
12. Rinkel, R. N., et al. (2009). The psychometric and clinical
validity of the SWAL-QOL questionnaire in evaluating swal-
lowing problems experienced by patients with oral and oropha-
ryngeal cancer. Oral Oncology, 45, 67–71.
13. Lam, P. M., & Lai, C. K. Y. (2011). The validation of the Chinese
version of the Swallow Quality of Life Questionnaire (SWAL-
QOL) using exploratory and confirmatory factor analysis. Dys-
phagia, 26(2), 117–124.
14. McHorney, C. A., et al. (2002). The SWAL-QOL and SWAL-
CARE outcomes for oropharyngeal dysphagiain adults: III. Doc-
umentation of reliability and validity. Dysphagia, 17, 97–114.
15. Bogaardt, H. C. A., et al. (2009). Cross-cultural adaptation and
validation of the Dutch version of SWAL-QOL. Dysphagia,
16. Fleiss, J. L. (Ed.). (1981). Statistical methods for rates and pro-
portions (2nd ed.). New York: Wiley.
17. Mokkink, L. B., et al. (2010). The COSMIN checklist for
assessing the methodological quality of studies on measurement
properties of health status measurements: an international Delphi
study. Qualitative Life Research, 19, 539–549.
18. Buck, D., et al. (2004). Development and validation of NEWS-
Qol, the Newcastle stroke -specific quality of life measure.
Cerebrovascular Diseases, 17, 143–152.
Qual Life Res (2013) 22:891–895 895