Epidemiology and outcomes in patients with anemia of CKD not on dialysis from a large US healthcare system database: a retrospective observational study.

Background: Optimal management of anemia of chronic kidney disease (CKD) remains controversial. This retrospective study aimed to describe the epidemiology and selected clinical outcomes of anemia in patients with CKD in the US.

Methods: Data were extracted from Henry Ford Health System databases. Adults with stages 3a-5 CKD not on dialysis (estimated glomerular filtration rate < 60 mL/min/1.73m) between January 1, 2013 and December 31, 2017 were identified. Patients on renal replacement therapy or with active cancer or bleeding were excluded. Patients were followed for ≥12 months until December 31, 2018. Outcomes included incidence rates per 100 person-years (PY) of anemia (hemoglobin < 10 g/dL), renal and major adverse cardiovascular events, and of bleeding and hospitalization outcomes. Adjusted Cox proportional hazards models identified factors associated with outcomes after 1 and 5 years.

Results: Among the study cohort (N = 50,701), prevalence of anemia at baseline was 23.0%. Treatments used by these patients included erythropoiesis-stimulating agents (4.1%), iron replacement (24.2%), and red blood cell transfusions (11.0%). Anemia incidence rates per 100 PY in patients without baseline anemia were 7.4 and 9.7 after 1 and 5 years, respectively. Baseline anemia was associated with increased risk of renal and major cardiovascular events, hospitalizations (all-cause and for bleeding), and transfusion requirements. Increasing CKD stage was associated with increased risk of incident anemia, renal and major adverse cardiovascular events, and hospitalizations.

Conclusions: Anemia was a prevalent condition associated with adverse renal, cardiovascular, and bleeding/hospitalization outcomes in US patients with CKD. Anemia treatment was infrequent.