Sundays and Mortality in Patients with AKI

Abstract

Initiation of dialysis on Sunday is limited by constraints that do not exist on other days of the week, which may lead to triaging of dialysis therapy. The study hypothesis was that patients with AKI on a Sunday would sustain higher mortality rates. Study participants (n=4970) were part of the retrospective University of Pennsylvania Health AKI cohort, which is composed of patients with severe inpatient AKI (characterized by a doubling of admission creatinine) who were hospitalized from January 1, 2004, to August 31, 2010. Patient-days (n=15,995) were included if the patient had AKI severity of Acute Kidney Injury Network (AKIN) stage 2 or greater and had not yet begun receiving dialysis. The association of day of the week and inpatient mortality was assessed with logistic regression of data updated daily, using robust variance estimators. The rate (95% confidence interval [CI]) of initiation of dialysis on Sunday was 2.5 (1.8 to 3.1) per 100 patient-days, compared with 3.8 (3.5 to 4.1) per 100 patient-days on other days of the week (P=0.001). Inpatient mortality (95% CI) among patients with severe AKI present on a Sunday was 30% (28% to 32%), compared with 31% (31% to 32%) on other days of the week (P=0.08). Inpatient mortality among patients who initiated dialysis on Sunday was 65% (52% to 79%), compared with 65% (61% to 70%) among those who initiated dialysis from Tuesday through Saturday (P=0.79). Patients who initiated dialysis on Monday had a lower mortality than those who initiated it on another day of the week (52% [40% to 64%] versus 65% [61% to 70%]; P=0.03). Despite a lower frequency of dialysis, patients with severe AKI on Sunday have mortality similar to that of patients with severe AKI on other days of the week.