title: Dramatically changing rates and reasons for hospitalization in multiple sclerosis.
abstract: OBJECTIVE
  We aimed to describe hospitalizations in the multiple sclerosis (MS) population, and to evaluate temporal trends in hospitalizations in the MS population compared to the general population.
  
  
  METHODS
  Using population-based administrative data, we identified 5,797 persons with MS and a matched general population cohort of 28,769 persons. Using general linear models, we evaluated temporal trends in hospitalization rates and length of stay in the 2 populations over the period 1984-2011.
  
  
  RESULTS
  In 1984 the hospitalization rate was 35 per 100 person-years in the MS population and 10.5 in the matched population (relative risk [RR] 3.33; 95% confidence interval: 1.67-6.64). Over the study period hospitalizations declined 75% in the MS population but only 41% in the matched population. The proportion of hospitalizations due to MS declined substantially from 43.4% in 1984 to 7.8% in 2011. The 3 most common non-MS-related reasons for admission in the MS population were diseases of the digestive, genitourinary, and circulatory systems. Admissions for bacterial pneumonia, influenza, urinary tract infections, and pressure ulcers occurred more often in the MS population than in the general population, while admissions for circulatory system disease and neoplasms occurred less often. Older age, male sex, and lower socioeconomic status were associated with increased hospitalization rates for non-MS-related reasons.
  
  
  CONCLUSIONS
  Although hospitalization rates have declined dramatically in the MS population over the last quarter century, they remain higher than in the general population. Admissions for MS-related reasons now constitute only a small proportion of the reasons for hospitalization.
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada. rmarrie@hsc.mb.ca.
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Elliott
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Marriott
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Cossoy
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Blanchard
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: Aruni
authors.initials: A
authors.lastname: Tennakoon
authors.affiliation: From the Departments of Internal Medicine (R.A.M., J.M., M.C.) and Community Health Sciences (R.A.M., L.E., J.B., A.T., N.Y.), University of Manitoba, Winnipeg; and Epidemiology and Surveillance (N.Y.), Public Health and Primary Care Division, Manitoba Health, Winnipeg, Manitoba, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Yu
mesh_terms: D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data / Q000639:trends; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000628:therapy*; D012737:Sex Factors; D012959:Socioeconomic Factors
references.citation: CMAJ. 2009 Jun 23;180(13):E118-25
references.pmid: 19546444
references.citation: Neurology. 2010 Feb 9;74(6):465-71
references.pmid: 20071664
references.citation: Crit Care Med. 1990 Nov;18(11):1282-6
references.pmid: 2225900
references.citation: Crit Care Med. 1994 Dec;22(12):2001-7
references.pmid: 7988140
references.citation: Mult Scler Relat Disord. 2013 Oct;2(4):355-61
references.pmid: 25877846
references.citation: Brain. 2012 Oct;135(Pt 10):2973-9
references.pmid: 22730559
references.citation: Neuroepidemiology. 2006;26(2):102-7
references.pmid: 16374035
references.citation: Crit Care Med. 2008 Oct;36(10):2787-93, e1-9
references.pmid: 18766102
references.citation: Neuroepidemiology. 2008;30(4):234-8
references.pmid: 18437030
references.citation: Mult Scler. 2013 Sep;19(10):1336-40
references.pmid: 23364857
references.citation: Neuroepidemiology. 2010;35(4):267-74
references.pmid: 20881430
references.citation: Neurology. 1993 Apr;43(4):655-61
references.pmid: 8469318
references.citation: N Engl J Med. 2006 Mar 2;354(9):911-23
references.pmid: 16510745
references.citation: Neuroepidemiology. 2010 Aug;35(2):93-9
references.pmid: 20551694
references.citation: N Engl J Med. 1999 Oct 28;341(18):1359-67
references.pmid: 10536129
references.citation: Am J Manag Care. 2012 Nov;18(11):735-42
references.pmid: 23198715
references.citation: Am J Public Health. 1992 May;82(5):703-10
references.pmid: 1566949
references.citation: Mult Scler. 2013 Jul;19(8):1113-9
references.pmid: 23263898
references.citation: J Neurol Sci. 2010 May 15;292(1-2):57-62
references.pmid: 20202651
references.citation: Eur J Neurol. 2013 Aug;20(8):1153-60
references.pmid: 23496086
references.citation: J Manag Care Pharm. 2010 Nov-Dec;16(9):703-12
references.pmid: 21067256
references.citation: Mult Scler. 2008 May;14(4):522-9
references.pmid: 18562507
references.citation: Eur J Neurol. 2009 Feb;16(2):262-7
references.pmid: 19138330
references.citation: Chest. 2002 Feb;121(2):539-48
references.pmid: 11834670
references.citation: Pharmacoeconomics. 2008;26(10):847-60
references.pmid: 18793032
references.citation: Neurology. 2002 Jan 8;58(1):37-43
references.pmid: 11781403
references.citation: Arch Intern Med. 2003 Jan 13;163(1):101-6
references.pmid: 12523923
references.citation: Neurology. 2005 Oct 11;65(7):1066-70
references.pmid: 16217060
references.citation: Neuroepidemiology. 2013;40(3):195-210
references.pmid: 23363936
references.citation: Neurology. 1998 Jun;50(6):1594-600
references.pmid: 9633699
references.citation: J Clin Epidemiol. 1994 Oct;47(10):1127-32
references.pmid: 7722546
references.citation: J Manag Care Pharm. 2007 Jan-Feb;13(1):44-52
references.pmid: 17269836
references.citation: Clin Gastroenterol Hepatol. 2006 Jun;4(6):731-43
references.pmid: 16631415
references.citation: Health Place. 1999 Jun;5(2):157-71
references.pmid: 10670997
references.citation: J Neurol Neurosurg Psychiatry. 2006 Aug;77(8):918-26
references.pmid: 16690691