title: Survival by time of day of hemodialysis in an elderly cohort.
abstract: BACKGROUND
  Patients with end-stage renal disease (ESRD) typically undergo hemodialysis (HD) during the morning or afternoon, with time of treatment generally based on space availability or patient preference. No studies have investigated variation in patient survival as a function of the time of day when they receive dialysis.
  
  
  OBJECTIVE
  To investigate the association of elderly patients' HD treatment shift with their continued survival, controlling for well-established HD-related mortality risk factors.
  
  
  METHODS
  An 11-year follow-up cohort study conducted among 242 ESRD patients aged 60 years or older who underwent HD at 58 dialysis facilities in Georgia either during a morning shift (n = 167) or an afternoon shift (n = 75) and who completed baseline (1988) [corrected] and follow-up (1991) interviews.
  
  
  METHODS
  Mortality from all causes occurring through July 7, 1999, as verified by death-certificate reviews, and compared by morning vs afternoon-shift HD.
  
  
  RESULTS
  Morning-shift HD patients survived significantly longer than afternoon-shift patients (median survival, 941 days vs 470 days; P<.001). A Cox proportional hazards model indicated that the morning shift was protective (relative risk, 0.71; 95% confidence interval, 0.53-0.95) independent of age, race, sex, body mass index, functional status, diabetic ESRD, cardiovascular comorbidity, weekly hours of dialysis, and months of dialysis.
  
  
  CONCLUSIONS
  Possible explanations for differential survival in association with morning vs afternoon dialysis include salutary effects of sleep in the morning or less efficient biochemical exchange during afternoon dialysis. Results from this cohort study may warrant prospective observational studies and randomized clinical trials that systematically alter the time of day at which HD is administered.
authors.affiliation: Department of Neurology, Emory University Medical School, WMRB 6000, 1639 Pierce Dr, Atlanta, GA 30322, USA. dbliwis@emory.edu
authors.forename: D L
authors.initials: DL
authors.lastname: Bliwise
authors.forename: N G
authors.initials: NG
authors.lastname: Kutner
authors.forename: R
authors.initials: R
authors.lastname: Zhang
authors.forename: K P
authors.initials: KP
authors.lastname: Parker
mesh_terms: D000368:Aged; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy; D008297:Male; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000401:mortality; D016019:Survival Analysis; D013995:Time