title: Back problems, comorbidities, and their association with wealth.
abstract: BACKGROUND
  Studies assessing the economic burden of back problems have given little consideration to the presence of comorbidities.
  
  
  OBJECTIVE
  To assess the difference in the value of wealth held by Australians who have back problems and varying numbers of chronic comorbidities.
  
  
  METHODS
  A cross-sectional study.
  
  
  METHODS
  Individuals aged 45 to 64 years in 2009: 4,388 with no chronic health conditions, 1,405 with back problems, and 3,018 with other health conditions.
  
  
  METHODS
  Total wealth (cash, shares, superannuation, investment property, and owner occupied home).
  
  
  METHODS
  Using a microsimulation model (Health&WealthMOD), logistic regression models were used to assess the odds of having any wealth. Linear regression models were used to assess the difference in the value of this wealth.
  
  
  RESULTS
  Those with back problems and two comorbidities had 0.16 (95% confidence interval [CI]: 0.06-0.42) times the odds and those with back problems and three or more comorbidities had 0.20 (95% CI: 0.11-0.38) times the odds of having accumulated some wealth than those with no chronic health conditions. Those with back problems and three or more comorbidities had a median value of total wealth of around $150,000, whereas those with back problems only and back problems and one comorbidity had a median value of total wealth of around $250,500. There was no significant difference in the amount of wealth accumulated by those with back problems and at least one comorbidity and those with other health conditions and the same number of comorbidities. However, those with only one health condition (excluding back problems) had 65% more wealth than those with back problems only (95% CI: 5.1-161.2).
  
  
  CONCLUSIONS
  This study highlights the importance of considering multiple morbidities when discussing the relationship between back problems and economic circumstances.
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, 92-94 Parramatta Rd, Camperdown, Sydney NSW 1450, Australia; School of Public Health, University of Sydney, Edward Ford Building (A27), NSW 2050, Australia.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Schofield
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, 92-94 Parramatta Rd, Camperdown, Sydney NSW 1450, Australia. Electronic address: emily.callander@sydney.edu.au.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Callander
authors.affiliation: NHMRC Clinical Trials Centre, University of Sydney, 92-94 Parramatta Rd, Camperdown, Sydney NSW 1450, Australia.
authors.forename: Rupendra N
authors.initials: RN
authors.lastname: Shrestha
authors.affiliation: University Centre for Rural Health-North Coast, 55-61 Uralba St, Lismore NSW 2480, Australia.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Passey
authors.affiliation: National Centre for Social and Economic Modelling, University of Canberra, Canberra ACT 2601, Australia.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Kelly
authors.affiliation: National Centre for Social and Economic Modelling, University of Canberra, Canberra ACT 2601, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Percival
mesh_terms: D000328:Adult; D001315:Australia; D001416:Back Pain / Q000150:complications / Q000191:economics* / Q000453:epidemiology; D002908:Chronic Disease; D015897:Comorbidity; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005260:Female; D054625:Healthcare Disparities / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors
keywords: Australia; Back problems; Comorbidity; Cost of illness; Economic resources; Wealth