title: Heterogeneity in fibromyalgia based upon cognitive and physical performance and psychological symptomology.
abstract: OBJECTIVE
  This study sought to investigate the existence of subgroups within a fibromyalgia (FM) sample based on physical and cognitive performance measures, as well as self-report psychological measures. A multisystem disorder characterized by widespread musculoskeletal pain and co-morbid conditions, FM can lead to declines in cognitive functioning and difficulty with psychological health.
  
  
  METHODS
  Community participants (n = 57 women) recruited from support groups and university center databases provided documentation of having met the criteria for diagnosis of FM. Measures included validated performance and self-report instruments. Analysis was completed using hierarchical cluster analysis; a four cluster solution was chosen for its level of interpretability. The resulting model identified four distinct subgroups based upon patterns of performance and symptomology. Significant group differences were found on pain, fatigue, stiffness, and level of physical activity.
  
  
  CONCLUSIONS
  Study results support the existence of subgroups among the FM population based on levels of cognitive and physical performance and psychological symptoms.
  
  
  CONCLUSIONS
  Nurse practitioners aware of potential subgroups within FM should be better prepared to recommend treatment options for patients that target subgroup characteristics (e.g., high vs. low levels of psychological symptoms).
authors.affiliation: University of St. Thomas, Minneapolis, Minnesota.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Follick
authors.affiliation: Department of Psychology, California State University, Fullerton, California.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Cherry
authors.affiliation: School of Nursing, California State University, Fullerton, California.
authors.forename: Dana N
authors.initials: DN
authors.lastname: Rutledge
authors.affiliation: Department of Psychology, California State University, Fullerton, California.
authors.forename: Laura
authors.initials: L
authors.lastname: Zettel-Watson
authors.affiliation: Department of Health Sciences, California State University, Fullerton, California.
authors.forename: C Jessie
authors.initials: CJ
authors.lastname: Jones
mesh_terms: D000368:Aged; D003071:Cognition; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology / Q000523:psychology; D013577:Syndrome
keywords: Fibromyalgia; chronic pain; clusters; cognitive performance; physical performance; symptoms