title: Reliability of a cognitive endpoint for use in a multiple sclerosis pharmaceutical trial.
abstract: OBJECTIVE
  Determine reliability and basic psychometric properties of a composite cognitive endpoint, MS-COG, for monitoring change in cognitive function in MS drug trials.
  
  
  BACKGROUND
  50% of MS patients have cognitive impairment that impacts ability to work and quality of life. We selected neuropsychological tests based on sensitivity to MS cognitive impairment, availability of alternate forms, cross-cultural utility, and feasibility for multicenter trials, and assessed the reliability and validity of a composite endpoint, MS-COG.
  
  
  METHODS
  Administered SRT, BVMT-R, PASAT, and SDMT to 60 MS patients at 4 US centers twice over 45days, along with symptom inventories by patients and informants.
  
  
  RESULTS
  The MS-COG had test-retest reliability of 0.91. Processing Speed and Memory indices had reliabilities of 0.89 and 0.86, with modest practice effects. Reliability was high for the RR MS and SP MS subgroups as well, with correlations of .90 and .93, respectively for MS-COG. Overall, 42% of subjects obtained MS-COG scores in the impaired range, with SP MS subjects performing 0.8 SD below RR MS subjects. Impairment correlated well (r=0.37 to 0.40) with informant reports but was inconsistent with patient report, with the least reliable assessments by those with greater symptom severity.
  
  
  CONCLUSIONS
  The MS-COG is a reliable, repeatable measure of MS cognitive functioning that is sensitive to cognitive impairment in SP MS and RR MS patients and feasible for multicenter clinical trials. Further development is warranted.
authors.affiliation: Psychology Department, Rusk Institute of Rehabilitation Medicine. Electronic address: Derlanger212@gmail.com.
authors.forename: David M
authors.initials: DM
authors.lastname: Erlanger
authors.affiliation: PanMedix, Inc.
authors.forename: Tanya
authors.initials: T
authors.lastname: Kaushik
authors.affiliation: Private Corporation.
authors.forename: Lauren S
authors.initials: LS
authors.lastname: Caruso
authors.affiliation: Neurology Department, SUNY at Buffalo.
authors.forename: Ralph H B
authors.initials: RH
authors.lastname: Benedict
authors.affiliation: Ferkauf Graduate School of Psychology, Yeshiva University.
authors.forename: F W
authors.initials: FW
authors.lastname: Foley
authors.affiliation: Neuropsychology Associates of Fairfax, Georgetown University Department of Neurology.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Wilken
authors.affiliation: Neurology Clinical Development, Biogen Idec.
authors.forename: Diego
authors.initials: D
authors.lastname: Cadavid
authors.affiliation: Research Center, Kessler Foundation.
authors.forename: John
authors.initials: J
authors.lastname: Deluca
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000188:drug therapy* / Q000523:psychology; D009483:Neuropsychological Tests; D011788:Quality of Life; D015203:Reproducibility of Results; D013028:Space Perception; D011795:Surveys and Questionnaires
keywords: Assessment; Cognition; Endpoint; Multiple sclerosis; Neuropsychology; Reliability