Psychometric properties of the German Stroke and Aphasia Quality of Life Scale 39 generic version

European Journal of Physical and Rehabilitation Medicine, vol. 61, pp. 425–436

Abstract

BACKGROUND: The international expert consensus core outcome set for post-stroke aphasia recommends the Stroke and Aphasia Quality of Life Scale - 39/generic (SAQOL-39g) for assessing patient-reported health-related quality of life. Cultural adaptations of the SAQOL-39g are mandatory in stroke rehabilitation. AIM: We adapted the original English SAQOL-39g into German and evaluated its psychometric quality. DESIGN: Evaluation of a self-report scale embedded in a prospective multicenter parallel group randomized waitlist-controlled trial on the effectiveness of intensive speech and language therapy. SETTING: Nineteen in- and outpatient aphasia rehabilitation centers in Germany. POPULATION: People with chronic post-stroke aphasia (N.=156) of all types and severity levels. METHODS: We followed applicable guidelines for cross-cultural test adaptations and psychometric evaluations. Psychometric analyses are based on the assessment before three weeks of intensive speech and language therapy (acceptability, internal consistency, validity; N.=156), on the assessments before and after three weeks of waiting in the control group (test-retest reliability; N.=78), and on the assessments before and after three weeks of intensive speech and language therapy (responsiveness; N.=156). RESULTS: The German SAQOL-39g was feasible across all aphasia severity grades (no missing data; no floor/ceiling effects). Internal consistency was excellent (Cronbach's α=0.90); test-retest reliability was moderate-to-good (intraclass-correlations: ICC=0.73 for single/0.85 for average measures). Both exploratory factor analyses and multidimensional scaling of proximity data/graphical network analysis supported the 3-dimensional structure (domains: physical, psychosocial, communication) of the English original version. Convergent (|r|=0.29 to 0.48) and discriminative (|r|=0.03 to 0.07) validities were acceptable. Responsiveness to intervention-induced change showed a small-to-medium treatment effect (group difference after intervention compared to waiting-list control: Cohen's d=0.34). CONCLUSIONS: The German SAQOL-39g is a reliable, valid and change-sensitive patient-reported outcome measure to assess the physical, communication and psychosocial quality of life in chronic post-stroke aphasia, with comparable psychometric properties and factorial structure to the original English version. CLINICAL REHABILITATION IMPACT: The German SAQOL-39g is an easy-to-administer and -score patient-reported scale that can be used in rehabilitation settings to measure health-related quality of life and support patient-centered goal setting in people with chronic post-stroke aphasia of different ages, stroke durations, severity and type of aphasia.

Authors 12

1. Caterina Breitenstein corresponding

   University of Münster

   Affiliation as printed

   Department of Neurology, University of Muenster, Muenster, Germany - breitens@uni-muenster.de

2. Katerina Hilari

   University of Lübeck · City St George's, University of London

   Affiliation as printed

   School of Health and Medical Sciences, City St George's, University of London, London, UK

   Department of Speech and Language Therapy, Institute of Health Sciences, University of Luebeck, Luebeck, Germany

3. Annette Baumgaertner

   University of Lübeck · Jade University of Applied Sciences

   Affiliation as printed

   Department of Speech and Language Therapy, Institute of Health Sciences, University of Luebeck, Luebeck, Germany

   Department of Technology and Health for People, Jade University of Applied Sciences, Oldenburg, Germany

4. Tanja Grewe

   Universitätsmedizin Greifswald · Universität Greifswald · Jade University of Applied Sciences

   Affiliation as printed

   Department of Technology and Health for People, Jade University of Applied Sciences, Oldenburg, Germany

   Department of Neurology, University Medicine of Greifswald, Greifswald, Germany

5. Agnes Flöel

   Ludwig-Maximilians-Universität München · Universitätsmedizin Greifswald · Universität Greifswald

   Affiliation as printed

   Department of Neurology, University Medicine of Greifswald, Greifswald, Germany

   Clinical Neuropsychology Research Group (EKN), Institute of Phonetics and Speech Processing, Ludwig-Maximilians-University, Munich, Germany

6. Wolfram Ziegler

   Ludwig-Maximilians-Universität München · University of Tübingen

   Affiliation as printed

   Clinical Neuropsychology Research Group (EKN), Institute of Phonetics and Speech Processing, Ludwig-Maximilians-University, Munich, Germany

   Institute for Clinical Epidemiology and Applied Biometry, University of Tuebingen, Tuebingen, Germany

7. Peter Martus

   University of Tübingen · University of Münster

   Affiliation as printed

   Institute for Clinical Epidemiology and Applied Biometry, University of Tuebingen, Tuebingen, Germany

   Department of Neurology, University of Muenster, Muenster, Germany

8. Erich Bernd Ringelstein Aachen Department of Neurology Clinical and Cognitive Neuroscience

   RWTH Aachen University · University of Münster

   Affiliation as printed

   Department of Neurology, University of Muenster, Muenster, Germany

   Clinical and Cognitive Neuroscience, Department of Neurology, RWTH Aachen University, Aachen, Germany

9. Walter Huber Aachen Department of Neurology Clinical and Cognitive Neuroscience

   RWTH Aachen University · University Hospital Ulm

   Affiliation as printed

   Clinical and Cognitive Neuroscience, Department of Neurology, RWTH Aachen University, Aachen, Germany

   Department of Neurology, University Hospital Ulm, Ulm, Germany

10. Karl Georg Hæusler Aachen Department of Neurology Clinical and Cognitive Neuroscience

    RWTH Aachen University · Heinrich Heine University Düsseldorf · University Hospital Ulm · St. Mauritius Therapieklinik

    Affiliation as printed

    Department of Neurology, University Hospital Ulm, Ulm, Germany

    Clinical and Cognitive Neuroscience, Department of Neurology, RWTH Aachen University, Aachen, Germany

    Medical Faculty, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany

    St. Mauritius Rehabilitation Centre, Meerbusch, Germany

11. Stefanie Bruehl Aachen Department of Neurology Clinical and Cognitive Neuroscience

    RWTH Aachen University · Heinrich Heine University Düsseldorf · St. Mauritius Therapieklinik

    Affiliation as printed

    Clinical and Cognitive Neuroscience, Department of Neurology, RWTH Aachen University, Aachen, Germany

    Medical Faculty, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany

    St. Mauritius Rehabilitation Centre, Meerbusch, Germany

    Department of Neurology, RWTH Aachen University, Aachen, Germany

12. Klaus Willmes Aachen Department of Neurology

    RWTH Aachen University

    Affiliation as printed

    Department of Neurology, RWTH Aachen University, Aachen, Germany