title: Clinimetric testing of the comprehensive cervical dystonia rating scale.
abstract: BACKGROUND
  The aim of this study was to test the clinimetric properties of the Comprehensive Cervical Dystonia Rating Scale. This is a modular scale with modifications of the Toronto Western Spasmodic Torticollis Rating Scale (composed of three subscales assessing motor severity, disability, and pain) now referred to as the revised Toronto Western Spasmodic Torticollis Scale-2; a newly developed psychiatric screening instrument; and the Cervical Dystonia Impact Profile-58 as a quality of life measure.
  
  
  METHODS
  Ten dystonia experts rated subjects with cervical dystonia using the comprehensive scale. Clinimetric techniques assessed each module of the scale for reliability, item correlation, and factor structure.
  
  
  RESULTS
  There were 208 cervical dystonia patients (73% women; age, 59 ± 10 years; duration, 15 ± 12 years). Internal consistency of the motor severity subscale was acceptable (Cronbach's alpha = 0.57). Item to total correlations showed that elimination of items with low correlations (<0.20) increased alpha to 0.71. Internal consistency estimates for the subscales for disability and pain were 0.88 and 0.95, respectively. The psychiatric screening scale had a Cronbach's alpha of 0.84 and satisfactory item to total correlations. When the subscales of the Toronto Western Spasmodic Torticollis Scale-2 were combined with the psychiatric screening scale, Cronbach's alpha was 0.88, and construct validity assessment demonstrated four rational factors: motor; disability; pain; and psychiatric disorders. The Cervical Dystonia Impact Profile-58 had an alpha of 0.98 and its construction was validated through a confirmatory factor analysis.
  
  
  CONCLUSIONS
  The modules of the Comprehensive Cervical Dystonia Rating Scale are internally consistent with a logical factor structure.
authors.affiliation: Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Comella
authors.affiliation: Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Perlmutter
authors.affiliation: Emory University, Atlanta, Georgia, USA.
authors.forename: Hyder A
authors.initials: HA
authors.lastname: Jinnah
authors.affiliation: Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Waliczek
authors.affiliation: Emory University, Atlanta, Georgia, USA.
authors.forename: Ami R
authors.initials: AR
authors.lastname: Rosen
authors.affiliation: National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Galpern
authors.affiliation: Mayo Clinic, Scottsdale, Arizona, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Adler
authors.affiliation: University of Rochester, Rochester, New York, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Barbano
authors.affiliation: Emory University, Atlanta, Georgia, USA.
authors.forename: Stewart A
authors.initials: SA
authors.lastname: Factor
authors.affiliation: Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Goetz
authors.affiliation: Baylor College of Medicine, Houston Texas, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
authors.affiliation: University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Reich
authors.affiliation: University of Florida Movement Disorders Center, Gainesville, Florida, USA.
authors.forename: Ramon L
authors.initials: RL
authors.lastname: Rodriguez
authors.affiliation: Beth Israel Medical Center, New York, New York, USA.
authors.forename: William L
authors.initials: WL
authors.lastname: Severt
authors.affiliation: University of Toronto, University Health Network, Toronto, Ontario, Canada.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Zurowski
authors.affiliation: University of Toronto, University Health Network, Toronto, Ontario, Canada.
authors.forename: Susan H
authors.initials: SH
authors.lastname: Fox
authors.affiliation: Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Stebbins
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000592:standards*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014103:Torticollis / Q000175:diagnosis*
keywords: Cervical Dystonia Impact Profile-58; Toronto Western Spasmodic Torticollis Rating Scale; cervical dystonia; focal dystonia; rating scale