title: Reliability and validity of the International Cooperative Ataxia Rating Scale: a study in 156 spinocerebellar ataxia patients.
abstract: To evaluate the efficacy of treatments in spinocerebellar ataxias (SCAs), appropriate clinical scales are required. This study evaluated metric properties of the International Cooperative Ataxia Rating Scale (ICARS) in 156 SCA patients and 8 controls. ICARS was found to be a reliable scale satisfying accepted criteria for interrater reliability, test-retest reliability, and internal consistency. Although validity testing was limited, we found evidence of validity of ICARS when ataxia disease stages and Barthel index were used as external criteria. On the other hand, our study revealed two major problems associated with the use of ICARS. First, the redundant and overlapping nature of several items gave rise to a considerable number of contradictory ratings. Second, a factorial analysis showed that the rating results were determined by four different factors that did not coincide with the ICARS subscales, thus questioning the justification of ICARS subscore analysis in clinical trials.
authors.affiliation: Department of Neurology, University Hospital of Bonn, Bonn, Germany. tanja.schmitz-huebsch@ukb.uni-bonn.de
authors.forename: Tanja
authors.initials: T
authors.lastname: Schmitz-Hübsch
authors.forename: Sophie
authors.initials: S
authors.lastname: Tezenas du Montcel
authors.forename: Laszlo
authors.initials: L
authors.lastname: Baliko
authors.forename: Sylvia
authors.initials: S
authors.lastname: Boesch
authors.forename: Sara
authors.initials: S
authors.lastname: Bonato
authors.forename: Roberto
authors.initials: R
authors.lastname: Fancellu
authors.forename: Paola
authors.initials: P
authors.lastname: Giunti
authors.forename: Christoph
authors.initials: C
authors.lastname: Globas
authors.forename: Jun-Suk
authors.initials: JS
authors.lastname: Kang
authors.forename: Berry
authors.initials: B
authors.lastname: Kremer
authors.forename: Caterina
authors.initials: C
authors.lastname: Mariotti
authors.forename: Bela
authors.initials: B
authors.lastname: Melegh
authors.forename: Maryla
authors.initials: M
authors.lastname: Rakowicz
authors.forename: Rafal
authors.initials: R
authors.lastname: Rola
authors.forename: Sylvie
authors.initials: S
authors.lastname: Romano
authors.forename: Lodger
authors.initials: L
authors.lastname: Schöls
authors.forename: Sandra
authors.initials: S
authors.lastname: Szymanski
authors.forename: Bart P C
authors.initials: BP
authors.lastname: van de Warrenburg
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Zdzienicka
authors.forename: Alexandra
authors.initials: A
authors.lastname: Dürr
authors.forename: Thomas
authors.initials: T
authors.lastname: Klockgether
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000503:physiopathology