title: Prescription of twice-weekly hemodialysis in the USA.
abstract: OBJECTIVE
  The purpose of this study was to investigate the frequency and characteristics of two hemodialysis sessions/week, to identify factors which influence or predict this prescription, and to examine the outcomes of patients receiving hemodialysis two times/week as compared to the more common treatment of three times/week.
  
  
  METHODS
  Data from a national sample of 15,067 adult hemodialysis patients were utilized to compare twice-weekly with thrice-weekly therapy by logistic regression.
  
  
  RESULTS
  Patients treated less than one year were more likely to be treated twice-weekly (6.1%) than patients on dialysis for one year or more (2.7%) (AOR = 1.49, p = 0.002). Treatment schedules also varied significantly by geographic region. Factors predictive of twice-weekly hemodialysis (p < 0.05) were older age, Caucasian race, female gender, higher serum albumin, lower serum creatinine levels, and lower body mass index. A higher estimated renal function at the start of ESRD was also predictive of a twice-weekly schedule among incident patients (AOR = 1.05, p = 0.05). In addition, Cox-adjusted survival analysis indicated a lower mortality risk (RR = 0.76, p = 0. 02) for twice-weekly hemodialysis compared to thrice-weekly among prevalent patients. For incident patients, however, the results were not significant when adjusted for GFR at ESRD onset (RR = 0.85, p = 0.31).
  
  
  CONCLUSIONS
  Geographic differences in prescribed treatment remained unexplained by measured characteristics. The survival advantage associated with twice-weekly hemodialysis is likely to be related to patient selection and greater residual renal function.
authors.affiliation: University of Michigan, Ann Arbor 48103, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Hanson
authors.forename: T E
authors.initials: TE
authors.lastname: Hulbert-Shearon
authors.forename: A O
authors.initials: AO
authors.lastname: Ojo
authors.forename: F K
authors.initials: FK
authors.lastname: Port
authors.forename: R A
authors.initials: RA
authors.lastname: Wolfe
authors.forename: L Y
authors.initials: LY
authors.lastname: Agodoa
authors.forename: J T
authors.initials: JT
authors.lastname: Daugirdas
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D055656:Prescriptions / Q000706:statistics & numerical data*; D011446:Prospective Studies; D006435:Renal Dialysis / Q000401:mortality / Q000706:statistics & numerical data*; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology