title: Validation of the NARCOMS registry: fatigue assessment.
abstract: Participants in the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry report disability using Performance Scales (PS), which assess eight domains. We aimed to validate the PS fatigue subscale (PSF) using the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale (MFIS) as external criteria. We measured correlations between the PSF and age, disease duration and PS subscales to assess construct validity. The PSF correlated strongly with the MFIS (r =0.72, P <0.0001) and FSS (r =0.75, P <0.0001). Correlations between the PSF and age, disease duration were low, indicating divergent validity. Correlations between the PSF and spasticity, sensory and mobility PS scales were moderate, indicating convergent validity. The PSF has adequate criterion and construct validity in MS.
authors.affiliation: Mellen Center for MS Treatment and Research, U10, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. marrier@ccf.org
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
authors.forename: Gary
authors.initials: G
authors.lastname: Cutter
authors.forename: Tuula
authors.initials: T
authors.lastname: Tyry
authors.forename: Olympia
authors.initials: O
authors.lastname: Hadjimichael
authors.forename: Denise
authors.initials: D
authors.lastname: Campagnolo
authors.forename: Timothy
authors.initials: T
authors.lastname: Vollmer
mesh_terms: D004185:Disability Evaluation; D005221:Fatigue / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D009103:Multiple Sclerosis / Q000150:complications* / Q000453:epidemiology*; D009656:North America / Q000453:epidemiology; D012042:Registries / Q000592:standards*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires