Association of an acute kidney injury follow-up clinic with patient outcomes and care processes: a cohort study

Rationale and 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 and Participants — Patients hospitalized with AKI in Ontario, Canada, from February 1, 2013, to September 30, 2017, at a single clinical center discharged not dependent on dialysis.

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 four patients who received standard care. Cox proportional hazard 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. Over a mean (SD) follow-up of 2.2 (1.3) 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 versus 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 ≥66 years who attended the AKI follow-up clinic were more likely to receive beta-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 post-discharge 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.