title: The Effect of Socioeconomic Class and Immigrant Status on Disease Activity in Rheumatoid Arthritis: Data from BARFOT, a Multi-Centre Study of Early RA.
abstract: BACKGROUND
  There have been no reports on the effect of immigrant status and socioeconomic status on outcome in rheumatoid arthritis (RA) in Sweden.
  
  
  METHODS
  Between 1992 and 2006, 2,800 patients were included in the BARFOT study on early RA in Sweden. Disease Activity Score 28 joints (DAS28), Health Assessment Questionnaire (HAQ), treatment and European League Against Rheumatism (EULAR) response criteria were registered. In 2010, 1,430 patients completed a questionnaire enquiring about demographics and lifestyle factors.
  
  
  RESULTS
  One hundred and thirty-nine of the 1,430 patients (9.7%) were immigrants. At baseline immigrants had higher mean HAQ (1.2 vs 0.97 for non-immigrants, p=0.001), DAS28 (5.6 vs 5.2, p=0.000), visual analog scale (VAS) pain (56 mm vs 45 mm, p=0.000), VAS global health (53 mm vs 44 mm, p=0.000) and tender joint count (TJC) (10 vs 8, p=0.000). These differences persisted for up to 2 years of follow-up (for HAQ, for up to 8 years of follow-up). Immigrant status did not have any effect on swollen joint count (SJC), ESR, CRP or EULAR response. Socioeconomic class did not have any effect on treatment or outcome.
  
  
  CONCLUSIONS
  Immigrants scored worse in pain, function and TJC for up to 2 years of follow-up, but they did not differ from non-immigrants in objective measures of inflammation or EULAR outcome. This could be due to different perceptions of health and pain and/or the stress of immigration. Socioeconomic class had no effect on treatment or outcome, and this could be due to the relatively egalitarian society in Sweden.
authors.affiliation: Research and Development Centre, Spenshult Rheumatology Hospital, Oskarström, Sweden.
authors.forename: Maria L E
authors.initials: ML
authors.lastname: Andersson
authors.affiliation: Department of Rheumatology, IKVL, Lund University, Lund, and Research and Development Centre, Spenshult Rheumatology Hospital, Oskarström, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bergman
authors.affiliation: Karlskrona Central Hospital, Karlskrona, Sweden ; Department of Rheumatology, IKVL, Lund University, Lund, and Research and Development Centre, Spenshult Rheumatology Hospital, Oskarström, Sweden.
authors.forename: Maria K
authors.initials: MK
authors.lastname: Söderlin
keywords: Rheumatoid arthritis; epidemiology.; immigrants; socioeconomic class