title: Geographical Heterogeneity of Multiple Sclerosis Prevalence in France.
abstract: BACKGROUND
  Geographical variation in the prevalence of multiple sclerosis (MS) is controversial. Heterogeneity is important to acknowledge to adapt the provision of care within the healthcare system. We aimed to investigate differences in prevalence of MS in departments in the French territory.
  
  
  METHODS
  We estimated MS prevalence on October 31, 2004 in 21 administrative departments in France (22% of the metropolitan departments) by using multiple data sources: the main French health insurance systems, neurologist networks devoted to MS and the Technical Information Agency of Hospitalization. We used a spatial Bayesian approach based on estimating the number of MS cases from 2005 and 2008 capture-recapture studies to analyze differences in prevalence.
  
  
  RESULTS
  The age- and sex-standardized prevalence of MS per 100,000 inhabitants ranged from 68.1 (95% credible interval 54.6, 84.4) in Hautes-Pyrénées (southwest France) to 296.5 (258.8, 338.9) in Moselle (northeast France). The greatest prevalence was in the northeast departments, and the other departments showed great variability.
  
  
  CONCLUSIONS
  By combining multiple data sources into a spatial Bayesian model, we found heterogeneity in MS prevalence among the 21 departments of France, some with higher prevalence than anticipated from previous publications. No clear explanation related to health insurance coverage and hospital facilities can be advanced. Population migration, socioeconomic status of the population studied and environmental effects are suspected.
authors.affiliation: Clinical and Evaluation department, Nancy University Hospital, Vandoeuvre-les-Nancy, France.
authors.forename: Diane
authors.identifier: http://orcid.org/0000-0002-8225-9248
authors.initials: D
authors.lastname: Pivot
authors.affiliation: EA 4360 Apemac, Lorraine University, Paris Descartes University, Nancy, France.|Department of Neurology, Nancy University Hospital, Nancy, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Debouverie
authors.affiliation: National Institute for Occupational Safety and Health, Vandoeuvre-lès-Nancy, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Grzebyk
authors.affiliation: Department of Neurology, Toulouse University Hospital, Toulouse, France.
authors.forename: David
authors.initials: D
authors.lastname: Brassat
authors.affiliation: Department of Neurology, Toulouse University Hospital, Toulouse, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Clanet
authors.affiliation: Department of Neurology, Clermont-Ferrand University Hospital, Clermont-Ferrand, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Clavelou
authors.affiliation: Department of Neurology, Lyon Hospices Civils - Pierre Wertheimer University Hospital, Lyon, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Confavreux
authors.affiliation: Department of Neurology, Rennes University Hospital, Rennes, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Edan
authors.affiliation: Ecoles des Hautes Etudes en Santé Publique, Rennes, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Leray
authors.affiliation: Department of Neurology, Dijon University Hospital, Dijon, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Moreau
authors.affiliation: Department of Neurology, Lyon Hospices Civils - Pierre Wertheimer University Hospital, Lyon, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Vukusic
authors.affiliation: National Institute for Occupational Safety and Health, Vandoeuvre-lès-Nancy, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Hédelin
authors.affiliation: Clinical and Evaluation department, Nancy University Hospital, Vandoeuvre-les-Nancy, France.|INSERM, CIC-EC, Nancy, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Guillemin
mesh_terms: D000367:Age Factors; D001499:Bayes Theorem; D003430:Cross-Sectional Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006760:Hospitalization; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology*; D015995:Prevalence; D012737:Sex Factors