title: Infection-related health care utilization among people with and without multiple sclerosis.
abstract: BACKGROUND
  Little is known about infection risk in multiple sclerosis (MS).
  
  
  OBJECTIVE
  We examined infection-related health care utilization in people with and without MS.
  
  
  METHODS
  Using population-based health administrative data from British Columbia, Canada, people with MS were followed from their first demyelinating claim (1996-2013) until death, emigration, or study end (2013). Infection-related hospital, physician, and prescription data of MS cases were compared with sex-, age-, and geographically matched controls using adjusted regression models. Sex and age differences (18-39, 40-49, 50-59, 60+ years) were explored.
  
  
  RESULTS
  Relative to 35,837 controls, 7179 MS cases were over twice as likely to be hospitalized for infection (adjusted odds ratio: 2.39; 95% confidence interval (CI): 2.16-2.65), had 41% more physician visits (adjusted rate ratio (aRR): 1.41; 95% CI: 1.36-1.47), and filled 57% more infection-related prescriptions (aRR: 1.57; 95% CI: 1.49-1.65). Utilization was disproportionately higher in MS men than women and was elevated across all ages. MS cases had nearly twice as many physician visits and two to three times more hospitalizations for pneumonia, urinary system infections, and skin infections (aRRs ranged from 1.6 to 3.3) and over twice as many hospitalizations for intestinal infections (aRR = 2.6) and sepsis (aRR = 2.2).
  
  
  CONCLUSIONS
  Infection-related health care utilization was increased in people with MS across all age groups, with a higher burden for men.
authors.affiliation: Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: José Ma
authors.initials: JM
authors.lastname: Wijnands
authors.affiliation: Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Elaine
authors.initials: E
authors.lastname: Kingwell
authors.affiliation: Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Yinshan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Departments of Psychiatry, Psychology, and Neuroscience, and Medicine, Dalhousie University, Halifax, NS, Canada.
authors.forename: John D
authors.initials: JD
authors.lastname: Fisk
authors.affiliation: College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Charity
authors.initials: C
authors.lastname: Evans
authors.affiliation: Departments of Internal Medicine and Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
authors.affiliation: Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Tremlett
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001955:British Columbia / Q000453:epidemiology; D003141:Communicable Diseases / Q000453:epidemiology / Q000628:therapy*; D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Multiple sclerosis; health care utilization; infections; population-based data