title: Level of education and multiple sclerosis risk after adjustment for known risk factors: The EnvIMS study.
abstract: BACKGROUND
  Several recent studies have found a higher risk of multiple sclerosis (MS) among people with a low level of education. This has been suggested to reflect an effect of smoking and lower vitamin D status in the social class associated with lower levels of education.
  
  
  OBJECTIVE
  The objective of this paper is to investigate the association between level of education and MS risk adjusting for the known risk factors smoking, infectious mononucleosis, indicators of vitamin D levels and body size.
  
  
  METHODS
  Within the case-control study on Environmental Factors In MS (EnvIMS), 953 MS patients and 1717 healthy controls from Norway reported educational level and history of exposure to putative environmental risk factors.
  
  
  RESULTS
  Higher level of education were associated with decreased MS risk (p trend = 0.001) with an OR of 0.53 (95% CI 0.41-0.68) when comparing those with the highest and lowest level of education. This association was only moderately reduced after adjusting for known risk factors (OR 0.61, 95% CI 0.44-0.83). The estimates remained similar when cases with disease onset before age 28 were excluded.
  
  
  CONCLUSIONS
  These findings suggest that factors related to lower socioeconomic status other than established risk factors are associated with MS risk.
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Norway/The Norwegian Multiple Sclerosis Competence Center, Department of Neurology, Haukeland University Hospital, Norway kjetil.bjornevik@igs.uib.no.
authors.forename: Kjetil
authors.initials: K
authors.lastname: Bjørnevik
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Norway/The Norwegian Multiple Sclerosis Competence Center, Department of Neurology, Haukeland University Hospital, Norway.
authors.forename: Trond
authors.initials: T
authors.lastname: Riise
authors.affiliation: The Norwegian Multiple Sclerosis Competence Center, Department of Neurology, Haukeland University Hospital, Norway/The KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Norway.
authors.forename: Marianna
authors.initials: M
authors.lastname: Cortese
authors.affiliation: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway/Department of Neurology, Akershus University Hospital, Norway.
authors.forename: Trygve
authors.initials: T
authors.lastname: Holmøy
authors.affiliation: Department of Clinical Neurology, University of Tromsø, Norway/Centre for Clinical Research and Education, University Hospital of North Norway, Norway.
authors.forename: Margitta T
authors.initials: MT
authors.lastname: Kampman
authors.affiliation: Department of Epidemiology and Biostatistics and Occupational Health, McGill University, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Magalhaes
authors.affiliation: The Norwegian Multiple Sclerosis Competence Center, Department of Neurology, Haukeland University Hospital, Norway/The KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Norway.
authors.forename: Kjell-Morten
authors.initials: KM
authors.lastname: Myhr
authors.affiliation: Department of Epidemiology and Biostatistics and Occupational Health, McGill University, Canada/Research Institute of the McGill University Health Centre, Canada.
authors.forename: Christina
authors.initials: C
authors.lastname: Wolfson
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Norway/Department of Clinical and Experimental Medicine, University of Sassari, Italy/Division of Medicine, McGill University, Canada.
authors.forename: Maura
authors.initials: M
authors.lastname: Pugliatti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004522:Educational Status; D005260:Female; D006801:Humans; D007244:Infectious Mononucleosis / Q000150:complications / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000209:etiology; D009664:Norway / Q000453:epidemiology; D012042:Registries; D012306:Risk; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D012923:Social Class; D014807:Vitamin D / Q000008:administration & dosage
chemical_list: D014807:Vitamin D
keywords: Multiple sclerosis; education; environmental risk factors; socioeconomic status