Abstract: TH-PO556

Does Longer Duration of Predialysis Care Improve Survival in People Treated with Dialysis?

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 307 CKD: Health Services, Disparities, Prevention

Authors

  • Liu, Ping, University of Calgary, Calgary, Alberta, Canada
  • Garg, Amit X., London Health Sciences Centre, London, Ontario, Canada
  • Johnson, John F., London Health Sciences Centre, London, Ontario, Canada
  • Verrelli, Mauro, University of Manitoba, Winnipeg, Manitoba, Canada
  • Zacharias, James M., University of Manitoba, Winnipeg, Manitoba, Canada
  • Abd elhafeez, Samar, High Institute of Public Health, Alexandria, Egypt
  • Tonelli, Marcello, University of Calgary, Calgary, Alberta, Canada
  • Ravani, Pietro, University of Calgary, Calgary, Alberta, Canada
  • Quinn, Robert R., University of Calgary, Calgary, Alberta, Canada
  • Oliver, Matthew J., Sunnybrook Health Sciences Center, Toronto, Ontario, Canada
  • Ronksley, Paul E., University of Calgary, Calgary, Alberta, Canada
  • Hemmelgarn, Brenda, University of Calgary, Calgary, Alberta, Canada
  • Quan, Hude, University of Calgary, Calgary, Alberta, Canada
  • Hiremath, Swapnil, University of Ottawa, Ottawa, Ontario, Canada
  • Bello, Aminu K., UNIVERSITY OF ALBERTA, Edmonton, Alberta, Canada
  • Blake, Peter G., London Health Sciences Centre, London, Ontario, Canada
Background

Guidelines recommend early referral to nephrology care for people with chronic kidney disease, based on observational studies showing that longer nephrology care before dialysis start (predialysis care, PDC) is associated with lower mortality after dialysis start. This association may be observed because PDC truly improves patient outcomes, or because healthier people with an uncomplicated course of disease will have both longer PDC and better outcomes. We designed this study to assess whether the survival benefit of longer PDC exists after accounting for the potential confounding effect of acute events (markers of disease course) that may also be affected by prior PDC.

Methods

We did a retrospective cohort study in adults with kidney failure who initiated dialysis not following a failed kidney transplant between 2004 and 2014 in five Canadian programs. Data were collected from medical records and double-reviewed by two investigators.

Results

Of the 3152 participants: 23% had no PDC; 8%, 10%, and 59% received 1-119, 120-364, and ≥365 days of PDC, respectively. When we ignored markers of acute events (including unplanned dialysis start and higher residual kidney function around dialysis start) as in prior studies, longer PDC was associated with lower mortality (Hazard Ratio120-364 vs. 0-119 d 0.60, 95% CI 0.46-0.78; HR≥365 vs. 0-119 d 0.60 (0.51-0.71), standard Cox model adjusted for demographics, laboratory and clinical characteristics). When we accounted for markers of acute events, this association was weaker and no longer significant (HR120-364 vs. 0-119 d 0.84 (0.60-1.18); HR≥365 vs. 0-119 d 0.88 (0.69-1.13), marginal structural Cox model).

Conclusion

Current guidelines on early nephrology referral are based on studies that may have overestimated the survival benefit of longer PDC, because they may have inadequately addressed confounding by occurrence of acute events.