Validation of the German version of the extended ALS functional rating scale as a patient-reported outcome measure
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The revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) is a well-established rating instrument to assess the functional status of ALS patients. A recent innovation was the addition of three further items designed to improve its sensitivity at lower levels of physical function (ALSFRS-Extension, ALSFRS-EX). Neither the ALSFRS-R nor the ALSFRS-EX has been validated in German yet. The aim of the present study was the validation of the German version of a self-administered form of the ALSFRS-EX. Seventy-six patients participated in the study. Psychometric analysis included reliability assessment and factorial analysis. To evaluate convergent validity, correlations between ALSFRS-EX items and the MRC score, spasticity, tongue movement, pulmonary function, ALSAQ-40 and Borg dyspnoea scales (upright and supine) were performed. Internal consistency as measured by Cronbach’s alpha (total scale 0.868, subscales 0.690–0.938) and corrected item to total correlations (all above 0.50) was high. Test–retest reliability assessed by Spearman’s rho (0.882–0.972) and Cohen’s Kappa (0.63–0.92) was also high. Principal component analysis with varimax rotation yielded a four-factor solution accounting for approximately 79 % of the variance. Clinical parameters were strongly correlated with respective items and subscores of the ALSFRS-EX (muscle strength 0.568–0.833 p < 0.01; spasticity −0.236 to −0.376 p < 0.05; tongue movement 0.437–0.818 p < 0.01; pulmonary function 0.485–0.577 p < 0.01). ALSAQ-40 and Borg score correlated highly with the corresponding ALSFRS-EX items. The German self-report version of the ALSFRS-EX possesses very good psychometric properties similar to the original scale including high internal consistency and test–retest reliability as well as excellent convergent validity.
KeywordsALS ALSFRS functional rating scale German version Validation Patient-reported outcome measure
The authors wish to express their gratitude to the patients who participated in this study. This work was supported by the Stiftung für Medizinische Wissenschaft, Frankfurt am Main (to SV) and by the excellence program of the state of Saxony-Anhalt (to HJH).
Conflicts of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
The study was approved by the institutional ethics committees of Hannover Medical School and the University of Magdeburg and has, therefore, been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
- 5.Kim HY, Park KH, Koh SH, Lee SC, Nam YH, Kim J, Kim SH (2007) Korean version of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised: a pilot study on the reliability and validity. J Korean Neurol Assoc 25:149–154Google Scholar
- 8.Atsuta N, Watanabe H, Ito M, Nakamura R, Senda J, Kato S, Sobue G (2011) Development of a telephone survey system for patients with amyotrophic lateral sclerosis using the ALSFRS-R (Japanese version) and application of this system in a longitudinal multicenter study. Brain Nerve 63:491–496PubMedGoogle Scholar
- 9.Kaufmann P, Levy G, Montes J, Buchsbaum R, Barsdorf AI, Battista V, Arbing R, Gordon PH, Mitsumoto H, Levin B, Thompson JL, QALS study group (2007) Excellent inter-rater, intra-rater, and telephone-administered reliability of the ALSFRS-R in a multicenter trial. Amyotroph Lateral Scler 8:42–46PubMedCrossRefGoogle Scholar
- 19.Jenkinson C, Fitzpatrick R, Brennan C, Bromberg M, Swash M (1999) Development and validation of a short measure of health status for individuals with amyotrophic lateral sclerosis/motor neurone disease: the ALSAQ-40. J Neurol 246 Suppl 3:III16-21Google Scholar
- 21.Cohen J (1988) Statistical power analysis for the behavioural sciences. Lawrence Erlbaum Associates, HillsdaleGoogle Scholar
- 23.Streiner DL, Norman GR (2003) Health measurement scales, 3rd edn. Oxford University Press, OxfordGoogle Scholar
- 24.Franchignoni F, Mora G, Giordano A, Volanti P, Chiò A (2013) Evidence of multidimensionality in the ALSFRS-R scale: a critical appraisal on its measurement properties using Rasch analysis. J Neurol Neurosurg Psychiatry Epub ahead of print 2013 doi: 10.1136/jnnp-2012-304701
- 28.Tanaka Y, Yoshikura N, Harada N, Yamada M, Koumura A, Sakurai T, Hayashi Y, Kimura A, Hozumi I, Inuzuka T (2012) Late-onset patients with sporadic amyotrophic lateral sclerosis in Japan have a higher progression rate of ALSFRS-R at the time of diagnosis. Intern Med 51:579–584PubMedCrossRefGoogle Scholar