title: Re-evaluating the volume-outcome relationship in hemodialysis patients.
abstract: OBJECTIVE
  We sought to determine whether dialysis patient mortality rates are associated with differences in dialysis facility size, and whether this relationship differs among higher risk diabetic and lower-risk non-diabetic patients.
  
  
  METHODS
  Using 186,554 adult end-stage renal disease patients initiating hemodialysis at standalone facilities in the United States between 1996 and 1999, we evaluated relationships between dialysis facility size and survival to 5 years. We performed separate analyses for patients with and without diabetes as their primary cause of end-stage renal disease. Facility size was defined according to the number of hemodialysis patients at year's end (small<or=60, medium 61-120, and large>or=120).
  
  
  RESULTS
  Increasing facility size was associated with a reduced risk of mortality at 4 years for both diabetic (HR=0.983 per 10 unit increase, 95% CI=0.967, 0.999) and non-diabetic patients (HR 0.977 per 10 unit increase, 95% CI=0.963, 0.992) dialyzing in small facilities, and for diabetic patients (HR 0.989 per 10 unit increase, 95% CI=0.980, 0.998) dialyzing in medium size facilities.
  
  
  CONCLUSIONS
  Smaller facility size is associated with increasing long-term mortality for in-center hemodialysis patients. This relationship appears to be more pronounced among higher-risk diabetic vs. lower-risk non-diabetic patients.
authors.affiliation: Duke Clinical Research Institute, 2400 Pratt Street, Room 0311, Durham, NC 27705, USA. eric.eisenstein@duke.edu
authors.forename: Eric L
authors.initials: EL
authors.lastname: Eisenstein
authors.forename: Jie L
authors.initials: JL
authors.lastname: Sun
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Anstrom
authors.forename: Judith A
authors.initials: JA
authors.lastname: Stafford
authors.forename: Lynda A
authors.initials: LA
authors.lastname: Szczech
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Muhlbaier
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Mark
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006276:Health Facility Size; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D006435:Renal Dialysis; D012189:Retrospective Studies; D016019:Survival Analysis; D014481:United States