Skip to main content
Erschienen in: Quality of Life Research 4/2013

Open Access 01.05.2013 | Brief Communication

The feasibility and test–retest reliability of the Dutch Swal-Qol adapted interview version for dysphagic patients with communicative and/or cognitive problems

verfasst von: Jessie Lemmens, Gerrie J. J. W. Bours, Martien Limburg, Anna J. H. M. Beurskens

Erschienen in: Quality of Life Research | Ausgabe 4/2013

Abstract

Purpose

The adaptation of the Dutch Swal-Qol questionnaire to an interview format suitable for dysphagic patients with communicative and/or cognitive problems and evaluation of the feasibility and test–retest reliability.

Methods

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.

Results

The constructed interview version was considered 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).

Conclusions

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 feasibility and does not compromise the test–retest reliability.

Introduction

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 [35]. Several studies give recommendations for adjustments for patient groups with communicative and cognitive problems [69]. McHorney et al. [10] 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 [1114]. However, the current self-report version 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 test–retest reliability.

Methods

Design

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 environment.

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 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 [14]. We adapted the Dutch translation of the Swal-Qol [15] into an interview version by using a two-step response method with supportive visual aids [69]. The adaptation process is described in Box 1.
Box 1
Swal-Qol adaptations, from self-report to interview version
https://static-content.springer.com/image/art%3A10.1007%2Fs11136-012-0202-y/MediaObjects/11136_2012_202_Tab1_HTML.gif

Participants

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 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 consent, it was asked for again.

Measurements

Patient characteristics

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 considered ‘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

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 were asked.

Test–retest reliability

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.

Procedures

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 status.

Data analyses

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 problems. 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 reliability 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 coefficients (ICC) were calculated.

Results

Participants

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.
Table 1
Sample characteristics (n = 57)
 
n (%)
Gender
 Male
24 (42)
Age
 Mean (SD)
75.1 (12.1)
 Min
46
 Max
94
Highest completed education
 Elementary school
22 (39)
 High school
16 (28)
 Vocational training
14 (25)
 University
5 (9)
Dysphagia
 Severe: tube feeding
9 (16)
 Moderate: oral intake with adjusted consistency
25 (47)
 Mild: normal oral intake with adaptive strategies
21 (37)
Communication and/or cognitive problemsa
41 (72)
 Communication problemsa
33 (58)
  Aphasia (language)
12 (21)
  Dysarthria (speech/voice)
12 (21)
  Buccofacial/verbal apraxia (speech)
5 (9)
  Unclassified diagnosis (speech/language)
4 (7)
 Cognitive problems (neuropsychological symptoms)a
12 (21)
  Amnesia
6 (11)
  Neglect/hemianopia
6 (11)
 None
16 (28)
aPatients can experience several problems in communication and/or cognition

Feasibility

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 sustain attention.
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.

Test–retest reliability

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 communicative 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).
Table 2
Test–retest reliability of the Swal-Qol subscales (n = 56)
Subscale (# items)
n
Total group (weighed kappa)
Total group (Spearman’s rho/ICC)
Subgroups (weighed kappa)
Problems with communication and/or cognition (n = 40)
No problems with communication/cognition (n = 16)
1 Burden (2)
56
0.849
0.854/0.850
0.862
0.815
2 Eating duration and desire (5)
54
0.822
0.828/0.817
0.811a
0.856
3 Dysphagia symptoms (14)
54
0.940
0.934/0.941
0.960a
0.779
4 Food selection (2)
53
0.823
0.834/0.818
0.836a
0.804a
5 Communication (2)
56
0.786
0.777/0.789
0.790
0.761
6 Fear (4)
53
0.675
0.715/0.678
0.677a
0.660a
7 Mental health (5)
55
0.898
0.877/0.891
0.879
0.946a
8 Social functioning (5)
48
0.908
0.909/0.909
0.931a
0.785a
9 Fatigue and sleep (5)
55
0.713
0.710/0.714
0.736
0.631a
Overall score (44)
48
0.953
0.951/0.952
0.960a
0.924a
a n is smaller than the group size given at the top of each subgroup

Discussion

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 demonstrated that our adaptations led to a scale applicable within 30 min in half of the cases. In comparison with previous 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 reliability 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 previous studies.
The absence of recent objective test results to estimate the communicative and/or cognitive problems might have influenced the group composition for the subgroup analysis. 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.

Acknowledgments

The authors would like to thank all the patients, SLTs and nursing homes for their participation. We acknowledge our assessors and especially L.H.J. Smeets for her contribution to this study.

Open Access

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Unsere Produktempfehlungen

e.Med Interdisziplinär

Kombi-Abonnement

Für Ihren Erfolg in Klinik und Praxis - Die beste Hilfe in Ihrem Arbeitsalltag

Mit e.Med Interdisziplinär erhalten Sie Zugang zu allen CME-Fortbildungen und Fachzeitschriften auf SpringerMedizin.de.

Literatur
1.
Zurück zum Zitat 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.PubMedCrossRef 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.PubMedCrossRef
2.
Zurück zum Zitat Williams, L.-S., et al. (1999). Measuring quality of life in a way that is meaningful to stroke patients. Neurology, 53(8), 1839–1843.PubMedCrossRef Williams, L.-S., et al. (1999). Measuring quality of life in a way that is meaningful to stroke patients. Neurology, 53(8), 1839–1843.PubMedCrossRef
3.
Zurück zum Zitat Price, C. I. M., Curless, R. H., & Rodgers, H. (1999). Can stroke patients use visual analogue scales. Stroke, 30, 1357–1361.PubMedCrossRef Price, C. I. M., Curless, R. H., & Rodgers, H. (1999). Can stroke patients use visual analogue scales. Stroke, 30, 1357–1361.PubMedCrossRef
4.
Zurück zum Zitat Williams, L.-S., et al. (1999). Development of a stroke-specific quality of life scale. Stroke, 30, 1362–1369.PubMedCrossRef Williams, L.-S., et al. (1999). Development of a stroke-specific quality of life scale. Stroke, 30, 1362–1369.PubMedCrossRef
5.
Zurück zum Zitat 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.PubMedCrossRef 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.PubMedCrossRef
6.
Zurück zum Zitat Doesborgh, S., et al. (2003). Linguistic deficits in the acute phase of stroke. Journal of Neurology, 250(8), 977–982.PubMedCrossRef Doesborgh, S., et al. (2003). Linguistic deficits in the acute phase of stroke. Journal of Neurology, 250(8), 977–982.PubMedCrossRef
7.
Zurück zum Zitat Lloyd, V., Gatherer, A., & Kalsy, S. (2006). Conducting qualitative interview research with people with expressive language difficulties. Qualitative Health Research, 16(10), 1386–1404.PubMedCrossRef Lloyd, V., Gatherer, A., & Kalsy, S. (2006). Conducting qualitative interview research with people with expressive language difficulties. Qualitative Health Research, 16(10), 1386–1404.PubMedCrossRef
8.
Zurück zum Zitat 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.PubMedCrossRef 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.PubMedCrossRef
9.
Zurück zum Zitat Dalemans, R., et al. (2010). Psychometric properties of the Community Integration Questionnaire adjusted for people with aphasia. Archives Physical and Medical Rehabilitation, 91(3), 395–399.CrossRef Dalemans, R., et al. (2010). Psychometric properties of the Community Integration Questionnaire adjusted for people with aphasia. Archives Physical and Medical Rehabilitation, 91(3), 395–399.CrossRef
10.
Zurück zum Zitat 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.PubMed 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.PubMed
11.
Zurück zum Zitat Khaldoun, E., Woisard, V., & Verin, E. (2009). Validation in French of the SWAL-QOL scale in patients with oropharyngeal dysphagia. Gastroenterologie Clinique et Biologique, 33, 167–171.PubMedCrossRef Khaldoun, E., Woisard, V., & Verin, E. (2009). Validation in French of the SWAL-QOL scale in patients with oropharyngeal dysphagia. Gastroenterologie Clinique et Biologique, 33, 167–171.PubMedCrossRef
12.
Zurück zum Zitat Rinkel, R. N., et al. (2009). The psychometric and clinical validity of the SWAL-QOL questionnaire in evaluating swallowing problems experienced by patients with oral and oropharyngeal cancer. Oral Oncology, 45, 67–71.CrossRef Rinkel, R. N., et al. (2009). The psychometric and clinical validity of the SWAL-QOL questionnaire in evaluating swallowing problems experienced by patients with oral and oropharyngeal cancer. Oral Oncology, 45, 67–71.CrossRef
13.
Zurück zum Zitat 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. Dysphagia, 26(2), 117–124.PubMedCrossRef 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. Dysphagia, 26(2), 117–124.PubMedCrossRef
14.
Zurück zum Zitat McHorney, C. A., et al. (2002). The SWAL-QOL and SWAL-CARE outcomes for oropharyngeal dysphagiain adults: III. Documentation of reliability and validity. Dysphagia, 17, 97–114.PubMedCrossRef McHorney, C. A., et al. (2002). The SWAL-QOL and SWAL-CARE outcomes for oropharyngeal dysphagiain adults: III. Documentation of reliability and validity. Dysphagia, 17, 97–114.PubMedCrossRef
15.
Zurück zum Zitat Bogaardt, H. C. A., et al. (2009). Cross-cultural adaptation and validation of the Dutch version of SWAL-QOL. Dysphagia, 24(1), 66–70.PubMedCrossRef Bogaardt, H. C. A., et al. (2009). Cross-cultural adaptation and validation of the Dutch version of SWAL-QOL. Dysphagia, 24(1), 66–70.PubMedCrossRef
16.
Zurück zum Zitat Fleiss, J. L. (Ed.). (1981). Statistical methods for rates and proportions (2nd ed.). New York: Wiley. Fleiss, J. L. (Ed.). (1981). Statistical methods for rates and proportions (2nd ed.). New York: Wiley.
17.
Zurück zum Zitat 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.CrossRef 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.CrossRef
18.
Zurück zum Zitat Buck, D., et al. (2004). Development and validation of NEWSQol, the Newcastle stroke -specific quality of life measure. Cerebrovascular Diseases, 17, 143–152.PubMedCrossRef Buck, D., et al. (2004). Development and validation of NEWSQol, the Newcastle stroke -specific quality of life measure. Cerebrovascular Diseases, 17, 143–152.PubMedCrossRef
Metadaten
Titel
The feasibility and test–retest reliability of the Dutch Swal-Qol adapted interview version for dysphagic patients with communicative and/or cognitive problems
verfasst von
Jessie Lemmens
Gerrie J. J. W. Bours
Martien Limburg
Anna J. H. M. Beurskens
Publikationsdatum
01.05.2013
Verlag
Springer Netherlands
Erschienen in
Quality of Life Research / Ausgabe 4/2013
Print ISSN: 0962-9343
Elektronische ISSN: 1573-2649
DOI
https://doi.org/10.1007/s11136-012-0202-y

Weitere Artikel der Ausgabe 4/2013

Quality of Life Research 4/2013 Zur Ausgabe