Journal
JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY
Volume 84, Issue 12, Pages 1340-1345Publisher
BMJ PUBLISHING GROUP
DOI: 10.1136/jnnp-2012-304701
Keywords
-
Categories
Funding
- Ministero della Salute (Ricerca Sanitaria Finalizzata) [RF-MAU-2007-643050]
- Centro Nazionale per la Prevenzione e il Controllo delle Malattie [31, 2009]
- European Community's Health Seventh Framework Programme [259867, 278611]
Ask authors/readers for more resources
Objective To examine dimensionality, reliability and validity of the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) using traditional classical test theory methods and Rasch analysis in order to provide a rationale for possible improvement of its metric quality. Methods Methodological research on ALSFRS-R collected in a consecutive sample of 485 patients with amyotrophic lateral sclerosis (ALS) attending three tertiary ALS centres. Results The ALSFRS-R items showed good internal consistency but dimensionality analysis argues against the use of ALSFRS-R as a single score because the scale lacks unidimensionality. Parallel analysis and exploratory factor analysis revealed three factors representing the following domains: (1) bulbar function; (2) fine and gross motor function; and (3) respiratory function. Rasch analysis showed that all items in each domain fitted the respective constructs to measure, except for item No 9 'climbing stairs' and item No 12 'respiratory insufficiency'. Rating categories did not comply with the criteria for category functioning. Collapsing the scale's 5 level ratings into 3 levels improved its metric quality. Conclusions The ALSFRS-R fails to satisfy rigorous measurement standards and should be, at least in part, revised. At present, ALSFRS-R should be considered as a profile of mean scores from three different domains (bulbar, motor and respiratory functions) more than a global total score. Further studies on ALSFRS-R using modern psychometric methods are warranted to confirm our findings and refine the metric quality of this scale, through a step by step process.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available