title: Clinical and economic characteristics of total hip replacement patients with high health care costs and high health care use.
abstract: OBJECTIVE
  The aims of this study were to confirm whether total hip arthroplasty (THA) patients with muscle atrophy/weakness (MAW) have high health care costs and resource use and to identify the characteristics that contribute to these high costs and use.
  
  
  METHODS
  This study analyzed claims from United States patients who underwent THA identified from commercial (n = 25,249) and Medicare (n = 22,472) insurance databases to compare demographics, health care costs, and resource use among patients with or without MAW. The patients were classified into three separate cohorts: pre-MAW (having MAW during the 12 mos before THA), post-MAW (having MAW during the 12 mos after THA, and no-MAW (no MAW claim). Characteristics of the THA patients associated with high health care costs were examined by multiple logistic regression, and subgroups of patients with high cost and high resource use were identified by classification and regression tree analyses.
  
  
  RESULTS
  Health care use and costs were significantly higher for the THA patients with MAW, who had greater likelihood of inpatient and emergency department use and stays at skilled nursing facilities than the no-MAW patients. Classification and regression tree identified subgroups of high-cost patients as those with MAW having extended hospital stays and more outpatient visits.
  
  
  CONCLUSIONS
  THA patients with MAW are at greater risk for high health care costs and resource consumption, including longer hospital stays, increased outpatient visits, and stays at skilled nursing and inpatient rehabilitation facilities.
authors.affiliation: From the Eli Lilly and Company (ZC, MS, ENB, RB); and inVentiv Health Clinical (YC), Indianapolis, Indiana.
authors.forename: Zhanglin
authors.initials: Z
authors.lastname: Cui
authors.forename: Michael
authors.initials: M
authors.lastname: Schoenfeld
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Elizabeth Nicole
authors.initials: EN
authors.lastname: Bush
authors.forename: Russel
authors.initials: R
authors.lastname: Burge
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000191:economics*; D016208:Databases, Factual; D005260:Female; D017048:Health Care Costs; D006296:Health Services / Q000706:statistics & numerical data*; D006620:Hip Fractures / Q000191:economics / Q000601:surgery*; D006760:Hospitalization / Q000191:economics; D006801:Humans; D038801:International Classification of Diseases; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000191:economics* / Q000601:surgery*; D009133:Muscular Atrophy / Q000191:economics* / Q000601:surgery*; D014481:United States