Hospital case volume and clinical outcomes in critically ill patients with acute kidney injury treated with dialysis

PURPOSE: To determine whether patients with severe acute kidney injury who receive dialysis (AKI-D) experience better outcomes at centres that care for more patients with AKI-D. MATERIALS AND METHODS: Linked administrative datasets where used to perform a retrospective cohort study of all critically ill patients in Ontario, Canada, who had a first episode of AKI-D between 2002 and 2011. Centre volume for a given year, was designated by calculating the mean number of patients treated with acute dialysis at that centre during that year and the one preceding it. Patients treated at that centre were then assigned to a centre volume quartile for that year. RESULTS: We identified 19,658 critically ill patients with AKI-D treated at 54 Ontario hospitals. Mortality and dialysis dependence at 90-days were 46% and 31%, respectively. Centre volume was not associated with mortality at 90 days (with quartile 1 as the reference, adjusted odds ratio (aOR) 1.16 (95% CI, 0.87 - 1.54) in quartile 2, aOR 1.17 (95% CI, 0.91 - 1.50) in quartile 3, and aOR 1.06 (95% CI, 0.81 - 1.41) in quartile 4). CONCLUSIONS: There are no Centre volume survival associations in the management of AKI-D despite high mortality and dependence rate.