title: Smoking at onset of rheumatoid arthritis (RA) and its effect on disease activity and functional status: experiences from BARFOT, a long-term observational study on early RA.
abstract: OBJECTIVE
  To assess the effects of smoking on disease outcome in a large cohort of patients with early rheumatoid arthritis (RA).
  
  
  METHODS
  Between 1996 and 2004, 1787 adult patients (disease duration ≤ 1 year) were included in the BARFOT early RA study in Sweden. Smoking status was recorded at inclusion in the study. Disease Activity Score using 28 joint counts (DAS28), C-reactive protein (CRP), Health Assessment Questionnaire (HAQ) score, rheumatoid factor (RF), antibodies to cyclic citrullinated peptide (anti-CCP), general health (GH) and pain visual analogue scales (VAS), and drug treatment were registered at inclusion and at follow-up at 3, 6, and 12 months. European League Against Rheumatism (EULAR) response and remission criteria were applied at 3, 6, and 12 months.
  
  
  RESULTS
  The proportion of patients who smoked at inclusion in the study fell from 29% in 1996 to 20% in 2004. There were no significant differences in disease activity at inclusion stratified according to smoking status. At 12 months of follow-up, 18% of current smokers at inclusion, 12% of previous smokers, and 11% of never smokers had high disease activity (DAS28 > 5.1, p = 0.005). Significantly fewer current smokers were in remission at 12 months (33%) compared to never smokers (36%) and previous smokers (42%) (p = 0.013). Current smoking at inclusion independently predicted poor EULAR response up to 12 months of follow-up.
  
  
  CONCLUSIONS
  The present study gives some support to earlier data indicating that RA patients who smoke have a more active disease but further studies are needed to confirm this.
authors.affiliation: Research and Development Centre, Spenshult Rheumatology Hospital, Oskarström, Sweden. maria.soderlin@spenshult.se
authors.forename: M K
authors.initials: MK
authors.lastname: Söderlin
authors.forename: I F
authors.initials: IF
authors.lastname: Petersson
authors.forename: S
authors.initials: S
authors.lastname: Bergman
authors.forename: B
authors.initials: B
authors.lastname: Svensson
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010456:Peptides, Cyclic / Q000276:immunology; D011379:Prognosis; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects*; D013548:Sweden
chemical_list: D000906:Antibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D002097:C-Reactive Protein; D012217:Rheumatoid Factor