Supplementary Material for: Acute Kidney Injury before Dialysis Initiation Predicts Adverse Outcomes in Hemodialysis Patients

Background: Acute kidney injury (AKI) is associated with increased morbidity and mortality. Mortality in end-stage renal disease (ESRD) patients is highest during the first year of dialysis. The impact of pre-ESRD AKI events on long-term outcomes in incident ESRD patients remains unknown. Methods: We evaluated a retrospective cohort of 47,341 incident hemodialysis patients from the United States Renal Data System with linked Medicare data for at least 2 years prior to hemodialysis initiation. We examined the impact of pre-ESRD AKI events in the 2-year pre-ESRD period on the type of vascular access used at hemodialysis initiation (central venous catheter (CVC) versus arteriovenous access), and 1-year all-cause mortality after initiating hemodialysis. Results: The mean age was 72 ± 11 years. Of the study cohort, 18% initiated hemodialysis with arteriovenous access, and 54% of patients had at least one pre-ESRD AKI event. One-year, all-cause mortality was 32%. Compared to 75% for patients without a pre-ESRD AKI event, 89% of patients with a pre-ESRD AKI event initiated hemodialysis with CVC than arteriovenous access (p < 0.001). A pre-ESRD AKI event was associated with lower adjusted odds of starting hemodialysis with an arteriovenous access (OR 0.47; 95% CI 0.44–0.50, p < 0.001), and higher adjusted odds of 1-year mortality (OR 1.36; 95% CI 1.30–1.42, p < 0.001). Conclusion: An AKI event prior to initiating hemodialysis independently increases the risk of CVC use and predicts 1-year mortality. Improving processes of care after AKI events may improve dialysis outcomes in patients who progress to ESRD.