title: Smoking, smoking cessation, and disease activity in a large cohort of patients with rheumatoid arthritis.
abstract: OBJECTIVE
  While cigarette smoking is the best-studied environmental factor contributing to rheumatoid arthritis (RA), no study to date has examined the influence of smoking cessation on disease activity. We examined this relationship in an observational cohort of patients with RA in the United States.
  
  
  METHODS
  Patients enrolled in the Consortium of Rheumatology Researchers of North America registry (CORRONA) were stratified into never, former, and current smokers at enrollment. Current smokers were further stratified into continued and ceased smoking groups during their followup in the registry. The primary outcome was change in Clinical Disease Activity Index (CDAI) at last visit in a multivariate, random-effects regression model accounting for multiple timepoints.
  
  
  RESULTS
  At last visit, there was no significant change in CDAI between ceased smokers and continued smokers (coefficient -0.00091, SE 0.0033, p = 0.7834). The study did confirm prior cross-sectional studies that current smokers have worse disease activity than former or never smokers.
  
  
  CONCLUSIONS
  In the short term, smoking cessation did not appear to influence change in disease activity over time.
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Boston, MA 02114, USA. mfisher6@partners.org
authors.forename: Mark C
authors.initials: MC
authors.lastname: Fisher
authors.forename: Marc C
authors.initials: MC
authors.lastname: Hochberg
authors.forename: Muhammad
authors.initials: M
authors.lastname: El-Taha
authors.forename: Joel M
authors.initials: JM
authors.lastname: Kremer
authors.forename: Cheng
authors.initials: C
authors.lastname: Peng
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Greenberg
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology* / Q000473:pathology*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation; D014481:United States / Q000453:epidemiology