title: Symptom cluster and quality of life in multiple sclerosis.
abstract: BACKGROUND
  There is abundant evidence that quality of life (QOL) is compromised in persons with multiple sclerosis (MS), but researchers have not yet examined the possible association between co-occurring symptoms and QOL in this population.
  
  
  OBJECTIVE
  The objective of this study was to examine the symptom cluster of fatigue, pain, depression, and perceived cognitive complaints and its association with QOL in individuals with MS.
  
  
  METHODS
  The sample included 133 individuals with a definite diagnosis of MS who completed a battery of self-report measures as part of a cross-sectional study of symptoms and physical activity. The battery included the Fatigue Severity Scale, the Center for Epidemiological Studies-Depression Scale, the short form of the McGill Pain Questionnaire, the Perceived Deficits Questionnaire, and the Multiple Sclerosis Impact Scale.
  
  
  RESULTS
  Results indicated that 1) there were moderate bivariate correlations between fatigue, depression, pain, and perceived cognitive complaint scores; 2) the correlations between scores from the pairs of symptoms were attenuated when expressed as partial correlations controlling for the covariance of the remaining pair of symptoms; 3) exploratory and confirmatory factor analyses supported a single-factor model for the associations among fatigue, depression, pain, and perceived cognitive complaint scores; 4) cluster analysis identified three subgroups differing in experiences of fatigue, depression, pain, and perceived cognitive complaints; and 5) analysis of variance indicated a possible dose-response relationship between worsening symptoms and psychological and physical domains of QOL.
  
  
  CONCLUSIONS
  Such findings provide emerging support for a dose-response relationship between worsening symptoms of fatigue, pain, depression, and perceived cognitive complaints and QOL in persons with MS.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. robmotl@uiuc.edu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
authors.forename: Yoojin
authors.initials: Y
authors.lastname: Suh
authors.forename: Madeline
authors.initials: M
authors.lastname: Weikert
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D003072:Cognition Disorders / Q000150:complications / Q000523:psychology; D003863:Depression / Q000150:complications / Q000523:psychology; D005163:Factor Analysis, Statistical; D005221:Fatigue / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology / Q000523:psychology*; D010146:Pain / Q000150:complications; D011788:Quality of Life