title: Psychological profiles in patients with Sjögren's syndrome related to fatigue: a cluster analysis.
abstract: OBJECTIVE
  Fatigue is a highly prevalent and debilitating symptom in the autoimmune disease SS. Although the disease process plays a role in fatigue, psychological factors may influence fatigue and the ability to deal with its consequences. Profiles of co-occurring psychological factors may suggest potential targets for the treatment of fatigue. The aim of this study was to identify psychological profiles in patients with SS and the accompanying levels of fatigue.
  
  
  METHODS
  Three hundred patients with primary SS (mean age 57 years, 93% female) completed questionnaires on fatigue (multidimensional fatigue inventory), physical activity cognitions (TAMPA-SK), illness cognitions, cognitive regulation, emotion processing and regulation [Toronto Alexithymia Scale 20, Emotion Regulation Questionnaire (ERQ), Berkeley Expressivity Questionnaire], coping strategies (Brief COPE) and social support.
  
  
  RESULTS
  Principal axis factor analysis (oblimin rotation) yielded six psychological factors: social support, negative thinking, positive thinking, emotional expressivity, avoidance and alexithymia (i.e. the inability to differentiate emotions). Using cluster analyses, these factors were grouped in four psychological profiles: functional (39%), alexithymic (27%), self-reliant (23%) and dysfunctional (11%). Irrespective of the psychological profile, the level of fatigue was substantially higher in patients than in the general population. Patients with a dysfunctional or an alexithymic profile reported more fatigue than those with a self-reliant profile.
  
  
  CONCLUSIONS
  Our study in SS yielded four psychological profiles that were differentially associated with fatigue. These profiles can be used to examine determinants and prognosis of fatigue as well as the possibility of customizing cognitive behavioural interventions for chronic fatigue.
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands N.vanLeeuwen@uu.nl.
authors.forename: Ninke
authors.initials: N
authors.lastname: van Leeuwen
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Ercolie R
authors.initials: ER
authors.lastname: Bossema
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Knoop
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Aike A
authors.initials: AA
authors.lastname: Kruize
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Hendrika
authors.initials: H
authors.lastname: Bootsma
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Johannes W J
authors.initials: JW
authors.lastname: Bijlsma
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands Department of Clinical and Health Psychology, Utrecht University, Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen and Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Rinie
authors.initials: R
authors.lastname: Geenen
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D003071:Cognition / Q000502:physiology; D015928:Cognitive Behavioral Therapy; D004644:Emotions / Q000502:physiology; D005221:Fatigue / Q000453:epidemiology* / Q000523:psychology* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012859:Sjogren's Syndrome / Q000150:complications* / Q000503:physiopathology / Q000523:psychology*; D012944:Social Support; D011795:Surveys and Questionnaires
keywords: Sjögren’s syndrome; clusters; cognitive behavioural therapy; coping; fatigue; psychology; subtypes