title: One third of hospital costs for atherothrombotic disease are attributable to readmissions: a linked data analysis.
abstract: BACKGROUND
  Cardiovascular disease is the most frequent cause of death in Australia, with an associated cost burden of 11% of Australian annual health expenditure of which 40% is for hospital admissions. We investigated health outcomes and the components of hospital expenditure in the two years after an atherothrombotic disease admission to a tertiary hospital in an Australian setting.
  
  
  METHODS
  Using data linkage we analysed two years of hospitalisation data and death records of all men and women aged 35-84 years with an admission to a Western Australian tertiary hospital for atherothrombotic disease in 2007. Costs were identified by matching the Australian refined diagnostic related group on the admission records to the published schedules of public and private hospital costs for the period of interest, and converted to 2013 Australian dollars.
  
  
  RESULTS
  Of 6172 patients studied (74% coronary, 20% cerebrovascular, 6% peripheral), 783 (13%) died during follow-up and 174 of these were in hospital case-fatalities at index. Thirty-two percent of patients (n = 1965) accounted for 3172 readmissions to hospital with one in three having multiple hospitalisations. The hazard ratio of atherothrombotic disease readmission was 1.45 (95% CI 1.27, 1.66) in those with more than one vascular territory affected compared to those with only one territory affected after controlling for age, sex, comorbidity, admission type, procedures, and episode length of stay. The total index plus 2-year admission cost for atherothrombotic disease was calculated at $101 million; $71 million for index, and $30 million for readmissions.
  
  
  CONCLUSIONS
  Among patients hospitalised with atherothrombotic disease, the cost of related rehospitalisations within 24 months is almost a third of the total. Much of the readmission costs fell within the first year. Whether readmissions and cost associated with atherothrombotic disease can be lowered through secondary prevention measures requires further investigation.
authors.affiliation: School of Population Health, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, Australia. emily.atkins@uwa.edu.au.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Atkins
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Geelhoed
authors.forename: Matthew
authors.initials: M
authors.lastname: Knuiman
authors.forename: Tom G
authors.initials: TG
authors.lastname: Briffa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000191:economics* / Q000453:epidemiology; D005260:Female; D017721:Hospital Costs; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000191:economics*; D013927:Thrombosis / Q000191:economics* / Q000453:epidemiology; D014904:Western Australia / Q000453:epidemiology
references.citation: Cardiovasc Ther. 2009 Fall;27(3):164-72
references.pmid: 19689615
references.citation: Cerebrovasc Dis. 2002;13 Suppl 1:1-6
references.pmid: 11803180
references.citation: Heart. 2013 Sep;99(18):1353-8
references.pmid: 23886604
references.citation: BMJ Open. 2013 Nov 20;3(11):e003813
references.pmid: 24259391
references.citation: Eur J Health Econ. 2013 Aug;14(4):655-65
references.pmid: 22777727
references.citation: Aust N Z J Public Health. 1999 Oct;23(5):453-9
references.pmid: 10575763
references.citation: Clin Ther. 2010 Jan;32(1):119-32; discussion 106-7
references.pmid: 20171418
references.citation: Am J Med. 2012 Sep;125(9):882-7.e1
references.pmid: 22748400
references.citation: Aust Health Rev. 2013 Sep;37(4):488-94
references.pmid: 23962415
references.citation: Lancet. 2005 Nov 19;366(9499):1773-83
references.pmid: 16298214
references.citation: JAMA. 2006 Feb 1;295(5):547-53
references.pmid: 16449620
references.citation: JAMA. 2007 Mar 21;297(11):1197-206
references.pmid: 17374814
references.citation: Heart. 2012 Oct;98(19):1449-56
references.pmid: 22821274
references.citation: Med J Aust. 2004 Aug 2;181(3):150-4
references.pmid: 15287833
references.citation: Circulation. 2006 May 16;113(19):2363-72
references.pmid: 16702489
references.citation: Stroke. 2011 Jan;42(1):227-76
references.pmid: 20966421
references.citation: Pharmacoeconomics. 2003;21(9):651-9
references.pmid: 12807366