title: A cross-sectional study of pain sensitivity, disease-activity assessment, mental health, and fibromyalgia status in rheumatoid arthritis.
abstract: BACKGROUND
  Pain remains the most important problem for people with rheumatoid arthritis (RA). Active inflammatory disease contributes to pain, but pain due to non-inflammatory mechanisms can confound the assessment of disease activity. We hypothesize that augmented pain processing, fibromyalgic features, poorer mental health, and patient-reported 28-joint disease activity score (DAS28) components are associated in RA.
  
  
  METHODS
  In total, 50 people with stable, long-standing RA recruited from a rheumatology outpatient clinic were assessed for pain-pressure thresholds (PPTs) at three separate sites (knee, tibia, and sternum), DAS28, fibromyalgia, and mental health status. Multivariable analysis was performed to assess the association between PPT and DAS28 components, DAS28-P (the proportion of DAS28 derived from the patient-reported components of visual analogue score and tender joint count), or fibromyalgia status.
  
  
  RESULTS
  More-sensitive PPTs at sites over or distant from joints were each associated with greater reported pain, higher patient-reported DAS28 components, and poorer mental health. A high proportion of participants (48%) satisfied classification criteria for fibromyalgia, and fibromyalgia classification or characteristics were each associated with more sensitive PPTs, higher patient-reported DAS28 components, and poorer mental health.
  
  
  CONCLUSIONS
  Widespread sensitivity to pressure-induced pain, a high prevalence of fibromyalgic features, higher patient-reported DAS28 components, and poorer mental health are all linked in established RA. The increased sensitivity at nonjoint sites (sternum and anterior tibia), as well as over joints, indicates that central mechanisms may contribute to pain sensitivity in RA. The contribution of patient-reported components to high DAS28 should inform decisions on disease-modifying or pain-management approaches in the treatment of RA when inflammation may be well controlled.
authors.affiliation: Arthritis UK Pain Centre, Division of ROD, University of Nottingham, Nottingham, UK. n.joharatnam@doctors.org.uk.
authors.forename: Nalinie
authors.initials: N
authors.lastname: Joharatnam
authors.affiliation: Arthritis UK Pain Centre, Division of ROD, University of Nottingham, Nottingham, UK. Dan.mcwilliams@nottingham.ac.uk.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: McWilliams
authors.affiliation: Department Rheumatology, Sherwood Forest Hospitals NHS Foundation Trust, Sutton-in-Ashfield, UK. Deborah.wilson@sfh-tr.nhs.uk.
authors.forename: Deborah
authors.initials: D
authors.lastname: Wilson
authors.affiliation: Arthritis UK Pain Centre, Division of ROD, University of Nottingham, Nottingham, UK. Maggiewheeler@hotmail.co.uk.
authors.forename: Maggie
authors.initials: M
authors.lastname: Wheeler
authors.affiliation: Department of Rheumatology, Nottingham University Hospitals NHS Trust, Nottingham, UK. Ira.pande@nuh.nhs.uk.
authors.forename: Ira
authors.initials: I
authors.lastname: Pande
authors.affiliation: Arthritis UK Pain Centre, Division of ROD, University of Nottingham, Nottingham, UK. David.walsh@nottingham.ac.uk.|Department Rheumatology, Sherwood Forest Hospitals NHS Foundation Trust, Sutton-in-Ashfield, UK. David.walsh@nottingham.ac.uk.|Arthritis UK Pain Centre, Academic Rheumatology, Clinical Sciences Building, City Hospital, Nottingham, UK. David.walsh@nottingham.ac.uk.
authors.forename: David A
authors.initials: DA
authors.lastname: Walsh
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods / Q000523:psychology; D017288:Pain Threshold / Q000523:psychology*