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.
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: Ming Tang; Chao Gao; Stephen A Goutman; Alexandr Kalinin; Bhramar Mukherjee; Yuanfang Guan; Ivo D Dinov Journal: Neuroinformatics Date: 2019-07
Authors: Christian Lunetta; Andrea Lizio; Valeria A Sansone; Nadia Maria Cellotto; Eleonora Maestri; Massimo Bettinelli; Valentina Gatti; Mario Giovanni Melazzini; Giovanni Meola; Massimo Corbo Journal: J Neurol Date: 2016-01 Impact factor: 4.849
Authors: Jesse M Cedarbaum; Diane Stephenson; Richard Rudick; Maria C Carrillo; Glenn Stebbins; Douglas Kerr; Jill Heemskerk; Wendy R Galpern; Petra Kaufmann; David Cella; Maria Isaac; Marc K Walton Journal: Neurotherapeutics Date: 2015-01 Impact factor: 7.620