title: Association between GFR estimated by multiple methods at dialysis commencement and patient survival.
abstract: OBJECTIVE
  The Initiating Dialysis Early and Late study showed that planned early or late initiation of dialysis, based on the Cockcroft and Gault estimation of GFR, was associated with identical clinical outcomes. This study examined the association of all-cause mortality with estimated GFR at dialysis commencement, which was determined using multiple formulas.
  
  
  METHODS
  Initiating Dialysis Early and Late trial participants were stratified into tertiles according to the estimated GFR measured by Cockcroft and Gault, Modification of Diet in Renal Disease, or Chronic Kidney Disease-Epidemiology Collaboration formula at dialysis commencement. Patient survival was determined using multivariable Cox proportional hazards model regression.
  
  
  RESULTS
  Only Initiating Dialysis Early and Late trial participants who commenced on dialysis were included in this study (n=768). A total of 275 patients died during the study. After adjustment for age, sex, racial origin, body mass index, diabetes, and cardiovascular disease, no significant differences in survival were observed between estimated GFR tertiles determined by Cockcroft and Gault (lowest tertile adjusted hazard ratio, 1.11; 95% confidence interval, 0.82 to 1.49; middle tertile hazard ratio, 1.29; 95% confidence interval, 0.96 to 1.74; highest tertile reference), Modification of Diet in Renal Disease (lowest tertile hazard ratio, 0.88; 95% confidence interval, 0.63 to 1.24; middle tertile hazard ratio, 1.20; 95% confidence interval, 0.90 to 1.61; highest tertile reference), and Chronic Kidney Disease-Epidemiology Collaboration equations (lowest tertile hazard ratio, 0.93; 95% confidence interval, 0.67 to 1.27; middle tertile hazard ratio, 1.15; 95% confidence interval, 0.86 to 1.54; highest tertile reference).
  
  
  CONCLUSIONS
  Estimated GFR at dialysis commencement was not significantly associated with patient survival, regardless of the formula used. However, a clinically important association cannot be excluded, because observed confidence intervals were wide.
authors.affiliation: Department of Renal Medicine, Royal North Shore Hospital, Sydney Medical School, University of Sydney, Sydney, Australia;, †Monash Medical Centre and Eastern Health Renal Units, Melbourne, Australia;, ‡Department of Renal Medicine, Auckland City Hospital, Auckland, New Zealand;, §Department of Nephrology, Children's Hospital at Westmead, Sydney School of Public Health, University of Sydney, Sydney, Australia;, ‖Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia;, ¶Centre for Transplantation and Renal Research, Westmead Millennium Institute, University of Sydney, Sydney, Australia, *Centre for Kidney Disease Research, University of Queensland at Princess Alexandra Hospital, Brisbane, Australia.
authors.forename: Muh Geot
authors.initials: MG
authors.lastname: Wong
authors.forename: Carol A
authors.initials: CA
authors.lastname: Pollock
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Cooper
authors.forename: Pauline
authors.initials: P
authors.lastname: Branley
authors.forename: John F
authors.initials: JF
authors.lastname: Collins
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Craig
authors.forename: Joan
authors.initials: J
authors.lastname: Kesselhut
authors.forename: Grant
authors.initials: G
authors.lastname: Luxton
authors.forename: Andrew
authors.initials: A
authors.lastname: Pilmore
authors.forename: David C
authors.initials: DC
authors.lastname: Harris
authors.forename: David W
authors.initials: DW
authors.lastname: Johnson
mesh_terms: D001315:Australia / Q000453:epidemiology; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D008954:Models, Biological; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome