title: Exploring the determinants of racial and ethnic disparities in total knee arthroplasty: health insurance, income, and assets.
abstract: OBJECTIVE
  To estimate national total knee arthroplasty (TKA) rates by economic factors, and the extent to which differences in insurance coverage, income, and assets contribute to racial and ethnic disparities in TKA use.
  
  
  METHODS
  US longitudinal Health and Retirement Study survey data for the elderly and near-elderly (biennial rounds 1994-2004) from the Institute of Social Research, University of Michigan.
  
  
  METHODS
  The outcome is dichotomous, whether the respondent received first TKA in the previous 2 years. Longitudinal, random-effects logistic regression models are used to assess associations with lagged economic indicators.
  
  
  METHODS
  Sample was 55,469 person-year observations from 18,439 persons; 663, with first TKA.
  
  
  RESULTS
  Racial/ethnic disparities in TKA were more prominent among men than women. For example, relative to white women, odds ratios (ORs) were 0.94, 0.46, and 0.79, for white, black, and Hispanic men, respectively (P < 0.05 for black men). After adjusting for economic factors, racial/ethnic differences in TKA rates for women essentially disappeared, while the deficit for black men remained large. Among Medicare-enrolled elderly, those with supplemental insurance may be more likely to have first TKA compared with those without it, whether the supplemental coverage was private [OR: 1.27; 95% confidence interval (CI): 0.82-1.96] or Medicaid (OR: 1.18; 95% CI: 0.93-1.49). Among the near-elderly (age 47-64), compared with the privately insured, the uninsured were less likely (OR: 0.61; 95% CI: 0.40-0.92) and those with Medicaid more likely (OR: 1.53; 95% CI: 1.03-2.26) to have first TKA.
  
  
  CONCLUSIONS
  Limited insurance coverage and financial constraints explain some of the racial/ethnic disparities in TKA rates.
authors.affiliation: Section of General Internal Medicine, Boston University School of Medicine, Boston, Massachusetts 01532, USA. hanchate@bu.edu
authors.forename: Amresh D
authors.initials: AD
authors.lastname: Hanchate
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Zhang
authors.forename: David T
authors.initials: DT
authors.lastname: Felson
authors.forename: Arlene S
authors.initials: AS
authors.lastname: Ash
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000191:economics* / Q000706:statistics & numerical data; D015897:Comorbidity; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D054625:Healthcare Disparities / Q000706:statistics & numerical data*; D006801:Humans; D007182:Income; D007348:Insurance, Health / Q000706:statistics & numerical data*; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017678:Sex Distribution; D012959:Socioeconomic Factors; D014481:United States