title: Demographic and comorbid disparities based on payer type in a total joint arthroplasty cohort: implications in a changing health care arena.
abstract: BACKGROUND
  The purpose of this study was to compare differences in demographic, functional, access to care, and comorbidity data between a Medicaid and Iowa Care (state Medicaid) insured patient cohort and Medicare and a Commercial Payer patient cohort undergoing lower extremity total joint arthroplasty (TJA).
  
  
  METHODS
  A retrospective review of 874 primary TKAs and THAs by a single surgeon at an academic institution between January, 2004 and June, 2008 was performed. Data on the primary insurance payer was used to stratify the cohort into two groups; Medicaid and Iowa Care (state Medicaid) insured and Medicare and commercial payer. Demographic, functional, access to care, and comorbidity data obtained from a standard preoperative survey were compared.
  
  
  RESULTS
  Of 874 primary TKAs and THAs, 18.3 % of patients were Medicaid and Iowa Care insured, while 81.7 % were insured by Medicare and commercial payer. Average age was 53.7 and 62.3 respectively, while average BMI was 35.2 and 32.9 respectively. The Medicaid and Iowa Care group was found to be 3 times more likely to smoke tobacco (25.2% v. 8.3%). Preoperative WOMAC Function scores were 33.9 and 46.8, respectively. Self reported diabetes was used as a general surrogate for health comorbidities and occurred in 12.3 % and 11.5%, respectively. Distance traveled was used as a general surrogate for access to care with averages of 92.5 miles and 62.8 miles, respectively.
  
  
  CONCLUSIONS
  The Medicaid and Iowa Care (state Medicaid) group had significantly higher rates of smoking, were significantly younger, and had significantly lower WOMAC scores (p<0.05) preoperatively. BMI comparison showed a trend to greater obesity in the Medicaid and Iowa Care cohort (p=0.056). Diabetes rates were comparable between the two cohorts. Medicaid and Iowa Care patients traveled 29.7 miles farther, suggesting they had less access to local orthopaedic care. There are major differences in comorbidities and patient demographics between payer types.
authors.affiliation: University of Iowa, Iowa, City, USA.
authors.forename: Lucian C
authors.initials: LC
authors.lastname: Warth
authors.forename: John J
authors.initials: JJ
authors.lastname: Callaghan
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Wells
authors.forename: Steve S
authors.initials: SS
authors.lastname: Liu
authors.forename: Alison
authors.initials: A
authors.lastname: Klaassen
authors.forename: Yubo
authors.initials: Y
authors.lastname: Gao
authors.forename: Richard C
authors.initials: RC
authors.lastname: Johnston
mesh_terms: D017677:Age Distribution; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D019538:Health Care Surveys / Q000706:statistics & numerical data; D006297:Health Services Accessibility / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D007348:Insurance, Health / Q000706:statistics & numerical data* / Q000639:trends; D007349:Insurance, Health, Reimbursement / Q000706:statistics & numerical data* / Q000639:trends; D007484:Iowa / Q000453:epidemiology; D008484:Medicaid / Q000706:statistics & numerical data* / Q000639:trends; D008875:Middle Aged; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
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