title: Cigarette smoking and progression in multiple sclerosis.
abstract: OBJECTIVE
  To investigate the influence of cigarette smoking on progression and disability accumulation in multiple sclerosis (MS).
  
  
  METHODS
  Information on past and present smoking of 364 patients with MS was obtained through a structured questionnaire survey. We used Kaplan-Meier analyses and Cox regression models to evaluate the influence of smoking on the development and age at onset of secondary progression, on the age at onset of progression in patients with primary progressive MS, and on the time from disease onset to Expanded Disability Status Scale (EDSS) scores 4.0 and 6.0 in all patients. We also investigated the correlation between smoked pack-years and EDSS scores and the rate of progression as measured with the Multiple Sclerosis Severity Score.
  
  
  RESULTS
  We found no significant associations between cigarette smoking and any of the used measures.
  
  
  CONCLUSIONS
  Our data suggest that cigarette smoking has no influence on disease progression or accumulation of disability in multiple sclerosis.
authors.affiliation: Department of Neurology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands. m.w.koch@neuro.umcg.nl
authors.forename: Marcus
authors.initials: M
authors.lastname: Koch
authors.forename: Annemarie
authors.initials: A
authors.lastname: van Harten
authors.forename: Maarten
authors.initials: M
authors.lastname: Uyttenboogaart
authors.forename: Jacques
authors.initials: J
authors.lastname: De Keyser
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D012044:Regression Analysis; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D011795:Surveys and Questionnaires