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Kidney Week

Abstract: PO0840

The Impact of Late Initiation of Chronic Dialysis on Mortality: A National Retrospective Cohort Study

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Worthen, George Laurence, Dalhousie University, Halifax, Nova Scotia, Canada
  • Clark, David, Dalhousie University, Halifax, Nova Scotia, Canada
  • More, Keigan, Dalhousie University, Halifax, Nova Scotia, Canada
  • Vinson, Amanda Jean, Dalhousie University, Halifax, Nova Scotia, Canada
  • Tennankore, Karthik K., Dalhousie University, Halifax, Nova Scotia, Canada

Current Canadian guidelines recommend deferring dialysis initiation in asymptomatic patients until the glomerular filtration rate (GFR) reaches 6 mL/min/1.73m2, (an “intent-to-defer” strategy). However, little is known about how dialysis initiation and post dialysis outcomes are impacted when patients start at or below this threshold.


We sought to characterize the impact of starting dialysis at or below 6 mL/min/1.73m2 in a national retrospective cohort study of incident dialysis patients from 2004-2019. Dialysis data (excluding Manitoba and Quebec) was acquired from the Canadian Organ Replacement Register (CORR) and linked to hospitalization data using the well-established discharge abstract database (DAD). The cohort was restricted to only those who initiated dialysis as an outpatient and with previous nephrology follow-up of three months or more. Time to death was compared for those starting at or below 6 ml/min/1.73m2 (using the CKD-EPI formula) to those initiating between an eGFR of 6-15 ml/min/1.73m2 and analyzed using an adjusted cox proportional hazard model.


A total of 63327 unique patients started dialysis from 2004-2019, of whom 39696 patients started dialysis as an outpatient after at least three months of nephrology follow-up. The mean age was 63+/-14, 68% were white, and 61% were male. 24% of the population started dialysis at an eGFR by CKD-EPI at or below 6 mL/min. Patients starting at 6 mL/min/1.73m2 or below were more likely to start dialysis with a CVC (59% vs 50%, p<0.001). During the study period 18979 patients died (48%). Starting dialysis at or below 6 mL/min/1.73m2 was associated with a longer time to death (HR 0.87; 95% CI 0.84,0.90) after adjusting for sex, race, age, dialysis access, diabetic kidney disease, and other comorbidities.


In this cohort of incident dialysis patients, those with an eGFR at or below 6 mL/min/1.73m2 had a lower risk for mortality compared with those starting with a higher eGFR. These findings support deferral of dialysis initiation beyond the threshold of 6 mL/min/1.73m2 in the absence of traditional indications.