title: Pain as an important predictor of psychosocial health in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To examine the evolution of psychosocial aspects of health-related quality of life in rheumatoid arthritis (RA) patients, and to identify their predictors.
  
  
  METHODS
  All patients within a Swiss RA cohort and a US RA cohort who completed a Short Form 36 (SF-36) scale at least twice within a 4-year period were included. The primary outcome was psychosocial health as measured by the mental component summary (MCS) score of the SF-36. The evolution of this outcome over time was analyzed using structural equation models, which distinguish between the stable, the variable, and the measurement error components of the outcome's variance.
  
  
  RESULTS
  A total of 15,282 patients (48,323 observations) were included. MCS scores were mostly stable over time (between 69% and 75% of the variance was not due to measurement error). The variable component of the SF-36 was mostly due to fluctuations at the moment of measurement and not to a global time trend of psychosocial health. Pain was the most important predictor of both the stable and variable components of psychosocial health, explaining ∼44% of the observed psychosocial health variance.
  
  
  CONCLUSIONS
  This large cohort study demonstrates that pain is the most important predictor of a patient's psychosocial health in RA patients. This suggests that physicians should place greater emphasis on pain management.
authors.affiliation: University Hospitals of Geneva and University of Geneva, Geneva, Switzerland. delphine.courvoisier@hcuge.ch
authors.forename: Delphine S
authors.initials: DS
authors.lastname: Courvoisier
authors.forename: Thomas
authors.initials: T
authors.lastname: Agoritsas
authors.forename: Jérôme
authors.initials: J
authors.lastname: Glauser
authors.forename: Kaleb
authors.initials: K
authors.lastname: Michaud
authors.forename: Fred
authors.initials: F
authors.lastname: Wolfe
authors.forename: Eva
authors.initials: E
authors.lastname: Cantoni
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Perneger
authors.forename: Axel
authors.initials: A
authors.lastname: Finckh
mesh_terms: D018771:Arthralgia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000523:psychology*; D008603:Mental Health; D008875:Middle Aged; D010147:Pain Measurement; D011237:Predictive Value of Tests; D011788:Quality of Life / Q000523:psychology*; D012720:Severity of Illness Index; D012940:Social Problems / Q000523:psychology*