title: Second-hand exposure to tobacco smoke and its effect on disease activity in Swedish rheumatoid arthritis patients. Data from BARFOT, a multicenter study of RA.
abstract: OBJECTIVE
  We studied the prevalence and effect on disease activity of ever having had second-hand exposure to tobacco smoke in Swedish rheumatoid arthritis (RA) patients who had never smoked.
  
  
  METHODS
  Between 1992 and 2005, 2,800 patients were included in the BARFOT early-RA study in Sweden. Disease Activity Score 28 joints (DAS28), C-reactive protein (CRP), Health Assessment Questionnaire (HAQ), rheumatoid factor (RF), general health and pain visual analogue scales (VAS), and drug treatment were registered at inclusion and at follow-up at 3, 6, and 12 months and 2 and 5 years. EULAR response criteria were applied at the same follow-up points. In 2010, a self-completion postal questionnaire was sent to 2,102 patients in the BARFOT study enquiring about lifestyle habits such as whether they had ever been exposed to tobacco smoke as a result of someone else smoking.
  
  
  RESULTS
  A total of 963/1,421 patients (68%) had had second-hand exposure to tobacco smoke. At 3, 6, and 12 months, at 2 years, and at 5 years of follow-up, there were no differences in EULAR response between patients who had never smoked and who had been exposed or had not been exposed second-hand to tobacco smoke (p=0.91, p=0.88, p=0.84, p=0.61 and p=0.85, respectively).
  
  
  CONCLUSIONS
  We did not find any association between second-hand exposure to tobacco smoke and disease activity in RA.
authors.affiliation: Research and Development Center, Spenshult Rheumatology Hospital, Oskarström, Sweden. maria.soderlin@spenshult.se
authors.forename: Maria K
authors.initials: MK
authors.lastname: Söderlin
authors.forename: Maria
authors.initials: M
authors.lastname: Andersson
authors.forename: Stefan
authors.initials: S
authors.lastname: Bergman
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D018771:Arthralgia / Q000175:diagnosis / Q000453:epidemiology; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006801:Humans; D007596:Joints / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D015995:Prevalence; D012217:Rheumatoid Factor / Q000097:blood; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D015415:Biomarkers; D014028:Tobacco Smoke Pollution; D002097:C-Reactive Protein; D012217:Rheumatoid Factor