Second-hand exposure to tobacco smoke and its effect on disease activity in Swedish rheumatoid arthritis patients. Data from BARFOT, a multicentre study of rheumatoid arthritis
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),
