Reliability and validity of the International Cooperative Ataxia Rating Scale: A study in 156 spinocerebellar ataxia patients

✍ Scribed by Tanja Schmitz-Hübsch; Sophie Tezenas du Montcel; Laszlo Baliko; Sylvia Boesch; Sara Bonato; Roberto Fancellu; Paola Giunti; Christoph Globas; Jun-Suk Kang; Berry Kremer; Caterina Mariotti; Bela Melegh; Maryla Rakowicz; Rafal Rola; Sylvie Romano; Lodger Schöls; Sandra Szymanski; Bart P.C. van de Warrenburg; Elzbieta Zdzienicka; Alexandra Dürr; Thomas Klockgether

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 104 KB
• Volume: 21
• Category: Article
• ISSN: 0885-3185
• DOI: 10.1002/mds.20781

✦ Synopsis

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 re-liability, 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.