title: Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7: Australian Orthopaedic Association National Joint Replacement Registry.
abstract: BACKGROUND
  The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia.
  
  
  METHODS
  Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006-7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk.
  
  
  RESULTS
  Females accounted for 46.9% of the 642 primary THR performed during 2006-7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70-79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups.
  
  
  CONCLUSIONS
  Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA.
authors.affiliation: Barwon Epidemiology and Biostatistics Unit, Barwon Health, Deakin University, Kitchener House, PO Box 281, Geelong, Victoria, 3220, Australia. sharob@barwonhealth.org.au
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Brennan
authors.forename: Tyman
authors.initials: T
authors.lastname: Stanford
authors.forename: Anita E
authors.initials: AE
authors.lastname: Wluka
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Henry
authors.forename: Richard S
authors.initials: RS
authors.lastname: Page
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Graves
authors.forename: Mark A
authors.initials: MA
authors.lastname: Kotowicz
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Nicholson
authors.forename: Julie A
authors.initials: JA
authors.lastname: Pasco
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000191:economics* / Q000706:statistics & numerical data*; D001315:Australia; D003430:Cross-Sectional Studies; D003695:Delivery of Health Care; D005260:Female; D006622:Hip Prosthesis / Q000191:economics* / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000191:economics / Q000601:surgery; D017064:Process Assessment, Health Care; D012042:Registries; D012737:Sex Factors; D012923:Social Class; D012955:Societies, Medical; D055815:Young Adult