Association of an Acute Kidney Injury Follow-up Clinic With Patient Outcomes and Care Processes: A Cohort Study

Abstract

Rationale & objective: To determine whether attendance at an acute kidney injury (AKI) follow-up clinic is associated with reduced major adverse kidney events.

Study design: Propensity-matched cohort study.

Setting & participants: Patients hospitalized with AKI in Ontario, Canada, from February 1, 2013, through September 30, 2017, at a single clinical center, who were not receiving dialysis when discharged.

Exposure: Standardized assessment by a nephrologist.

Outcomes: Time to a major adverse kidney event, defined as death, initiation of maintenance dialysis, or incident/progressive chronic kidney disease.

Analytical approach: Propensity scores were used to match each patient who attended an AKI follow-up clinic to 4 patients who received standard care. Cox proportional hazards models were fit to assess the association between the care within an AKI follow-up clinic and outcomes. To avoid immortal time bias, we randomly assigned index dates to the comparator group.

Results: We matched 164 patients from the AKI follow-up clinic to 656 patients who received standard care. During a mean follow-up of 2.2±1.3 (SD) years, care in the AKI follow-up clinic was not associated with a reduction in major adverse kidney events relative to standard care (22.1 vs 24.7 events per 100 patient-years; HR, 0.91 [95% CI, 0.75-1.11]). The AKI follow-up clinic was associated with a lower risk of all-cause mortality (HR, 0.71 [95% CI, 0.55-0.91]). Patients aged at least 66 years who attended the AKI follow-up clinic were more likely to receive β-blockers (HR, 1.34 [95% CI, 1.02-1.77]) and statins (HR, 1.35 [95% CI, 1.05-1.74]), but not angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (HR, 1.21 [95% CI, 0.94-1.56]).

Limitations: Single-center study and residual confounding.

Conclusions: Specialized postdischarge follow-up for AKI survivors was not associated with a lower risk of major adverse kidney events but was associated with a lower risk of death and increased prescriptions for some cardioprotective medications.

Keywords: AKI survivors; CKD progression; Major adverse kidney events (MAKE); acute kidney injury (AKI); cardioprotective medications; chronic kidney disease (CKD); follow-up care; hospital discharge; hospitalization; kidney function monitoring; mortality; nephrology care; post-AKI care; postdischarge care; transitions of care.