title: Peritoneal and hemodialysis: I. Differences in patient characteristics at initiation.
abstract: BACKGROUND
  Comparisons of mortality outcomes between peritoneal dialysis (PD) and hemodialysis (HD) patients have shown varying results, which may be caused by the unequally distributed clinical conditions of patients at initiation. To address this issue, we evaluated the clinical characteristics of 105,954 patients at the initiation of PD and HD, using the U.S. national incidence data on treated end-stage renal disease from the Medical Evidence Form, 1995 to 1997.
  
  
  METHODS
  A general linear model was used to analyze differences of age, albumin, creatinine, blood urea nitrogen (BUN), and hematocrit; categorical data analysis to evaluate body mass index (BMI), grouped into four categories: < 19, 19-25 (< 25), 25-30 (< 30), and 30+; and logistic regression to assess the likelihood of initiating PD versus HD. Diabetics (DM) were analyzed separately from non-diabetics (NDM). Explanatory variables in the logistic regression included incidence year, race, gender, age, BMI, albumin, creatinine, BUN, and hematocrit. Race included white and black. Age was categorized into four groups: 20-44, 45-64, 65-74, and 75+.
  
  
  RESULTS
  At the initiation of dialysis PD patients were approximately 6 years younger (P < 0.0001) than HD patients. PD patients also had higher (P < 0.0001) albumin (+0.35 g/dL for DM and +0.23 g/dL for NDM) and hematocrit (+1.64% for DM and +1.71% for NDM) levels, and lower (P < 0.04) BUN (-8.75 mg/dL for DM and -5.24 mg/dL for NDM) and creatinine (-0.51 mg/dL for DM and -0.23 mg/dL for NDM) levels than HD patients. Whites had a higher (P < 0.0001) likelihood of starting PD than blacks, and patients with BMI <19 had a lower (P < 0.0001) chance of beginning on PD.
  
  
  CONCLUSIONS
  PD patients had favorable clinical conditions at the initiation of dialysis, which should be taken into consideration when comparing dialysis outcomes between the two modalities.
authors.affiliation: USRDS Coordinating Center and Minneapolis Medical Research Foundation, MN 55404, USA. jxue@usrds.org
authors.forename: Jay L
authors.initials: JL
authors.lastname: Xue
authors.forename: Shu-Cheng
authors.initials: SC
authors.lastname: Chen
authors.forename: James P
authors.initials: JP
authors.lastname: Ebben
authors.forename: Edward G
authors.initials: EG
authors.lastname: Constantini
authors.forename: Susan E
authors.initials: SE
authors.lastname: Everson
authors.forename: Eric T
authors.initials: ET
authors.lastname: Frazier
authors.forename: Lawrence Y
authors.initials: LY
authors.lastname: Agodoa
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Collins
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People; D014487:Centers for Medicare and Medicaid Services, U.S. / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D010530:Peritoneal Dialysis / Q000401:mortality*; D006435:Renal Dialysis / Q000401:mortality*; D017678:Sex Distribution; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D044465:White People; D001741:Black or African American