title: The effect of dialysis chains on mortality among patients receiving hemodialysis.
abstract: OBJECTIVE
  To examine the association between dialysis facility chain affiliation and patient mortality.
  
  
  METHODS
  Medicare dialysis population.
  
  
  METHODS
  Data from the United States Renal Data System (USRDS) were used to identify 3,601 free-standing dialysis facilities and 34,914 Medicare patients' incidence to end-stage renal disease (ESRD) in 2004. Mixed-effect regression models were used to estimate patient mortality by dialysis facility chain and profit status during the 2-year follow-up.
  
  
  METHODS
  USRDS data were matched with facility, cost, and census data.
  
  
  RESULTS
  Of the five largest dialysis chains, the lowest mortality risk was observed among patients dialyzed at nonprofit (NP) Chain 5 facilities. Compared with Chain 5, hazard ratios were 19 percent higher (95 percent CI 1.06-1.34) and 24 percent higher (95 percent CI 1.10-1.40) for patients dialyzed at for-profit (FP) Chain 1 and Chain 2 facilities, respectively. In addition, patients at FP facilities had a 13 percent higher risk of mortality than those in NP facilities (95 percent CI 1.06-1.22).
  
  
  CONCLUSIONS
  Large chain affiliation is an independent risk factor for ESRD mortality in the United States. Given the movement toward further consolidation of large FP chains, reasons behind the increase in mortality require scrutiny.
authors.affiliation: Medical Technology and Practice Patterns Institute, 4733 Bethesda Ave., Bethesda, MD 20814, USA. yz@mtppi.org
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Cotter
authors.forename: Mae
authors.initials: M
authors.lastname: Thamer
mesh_terms: D000368:Aged; D000554:Ambulatory Care Facilities; D005260:Female; D006269:Health Facilities, Proprietary; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D009026:Mortality; D009096:Multi-Institutional Systems; D015999:Multivariate Analysis; D011787:Quality of Health Care; D006435:Renal Dialysis; D012189:Retrospective Studies; D016019:Survival Analysis; D014481:United States