Anemia Management in Incident Dialysis Patients over Three Eras in Canada

Kidney Week 2020

Amid safety concerns raised following trials of target hemoglobin, several jurisdictions have adopted a more conservative approach to management of anemia in patients receiving hemodialysis. Outside of the United States, there are few data available regarding whether the conservative approach is associated with a change in outcomes.

Mark Canney, PhD, and colleagues in Canada conducted a retrospective national cohort study to examine the association between the era of anemia management and major clinical outcomes in incident dialysis patients. Results of the study were reported during a virtual poster session at ASN Kidney Week 2020 in a poster titled Temporal Trends in Anemia Management and Major Clinical Outcomes in Incident Dialysis Patients in Canada.

The researchers utilized the Canadian Organ Replacement Register to identify 35,945 adult patients who initiated hemodialysis or peritoneal dialysis from January 1, 2007, to December 31, 2015. To capture outcomes via data linkage with hospital discharge diagnoses, the study defined time at risk starting on day 90 of dialysis and continuing for a minimum of 12 months.

Patients were categorized into three time periods anchored to landmark target hemoglobin trials and publication of anemia guidelines: Era 1 (January 2007-December 2009); Era 2 (January 2010-December 2012; and Era 3 (January 2013-December 2015). The primary outcome was a composite of acute myocardial infarction (AMI), stroke, or mortality. The association between era and the primary outcome was examined using Cox proportional hazards regression models.

There was a decrease in mean hemoglobin at initiation of dialysis from 102.9/L in 2007 to 95.5 g/L in 2015, corresponding with a doubling in the prevalence of hemoglobin <80 g/L (8% to 17%) and a reduction in erythropoiesis-stimulating agent (ESA) use (49% to 44%).

During 66,844 person-years of follow-up, there were 11,810 events observed. Following multivariable adjustment, Era 3 was associated with an 8% relative risk reduction in the primary outcome compared with Era 1 (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.88-0.96). The reduction in risk was driven by a reduction in all-cause mortality (HR, 0.90; 95% CI, 0.85-0.94). There was no reduction in AMI or stroke. In a model without era, hemoglobin and use of an ESA were not independent predictors of mortality.

“There have been modest declines in average hemoglobin values and ESA use among incident dialysis patients in Canada. Unlike the US, there has been no temporal reduction in stroke. Patient survival has improved over time, likely for reasons other than anemia management. An increasing number of patients are starting dialysis with a hemoglobin <80 g/L, which represents a substantial shift in practice and merits further investigation in terms of patient-centered outcomes,” the researchers said.

Source: Canney M, Birks PC, Shao S, Parfrey P, Djurdjev O, Levin A. Temporal trends in anemia management and major clinical outcomes in incident dialysis patients in Canada. Abstract of a poster presented at the American Society of Nephrology virtual Kidney Week 2020 (PO0271), October 22, 2020.