Long-term healthcare utilization and associated costs after dialysis-treated acute kidney injury in children

Rationale and Objective — Acute kidney injury (AKI) is common among hospitalized children and is associated with increased hospital length of stay and costs. However, there are limited data on post-discharge healthcare utilization after AKI hospitalization. Our objectives were to evaluate healthcare utilization and physician follow-up patterns after pediatric dialysis-treated AKI.

Study Design — Retrospective cohort study, using provincial health administrative databases.

Setting and Participants — All hospitalized children (0-18yr) between 1996-2017 in Ontario, Canada. Exclusions: Non-Ontario residents, metabolic disorders or poisoning, and dialysis or kidney transplant (pre-admission or by 3mo post-discharge).

Exposure — Episodes of dialysis-treated AKI, identified using validated health administrative codes. AKI survivors were matched to four hospitalized controls without dialysis-treated AKI by age, sex, and admission year.

Outcomes — Our primary outcome was post-discharge hospitalizations, emergency department, and outpatient physician visits. Secondary outcomes included outpatient visits by physician type and composite healthcare costs.

Analytical Approach — Proportions with ≥1 event and rates (per 1,000 person-years). Total and median composite healthcare costs. Adjusted rate ratios (aRR) using negative binomial regression models.

Results — We included 1688 pediatric dialysis-treated AKI survivors and 6752 matched controls. Dialysis-treated AKI survivors had higher re-hospitalization and emergency department visit rates (0-1yr, 0-5yr, 0-10yr, and throughout follow-up), and outpatient visit rates (0-1yr). The overall aRR for re-hospitalization was 1.46 (95% confidence interval (CI) 1.25-1.69, p<0.0001) and outpatient visits was 1.16 (95%CI 1.09-1.23, p=0.01). Dialysis-treated AKI survivors also had higher healthcare costs. Nephrologist follow-up was infrequent among dialysis-treated AKI survivors (18.6% by 1yr post-discharge).

Limitations — Potential miscoding of study exposures or outcomes. Residual uncontrolled confounding. Data for healthcare costs and emergency department visits was unavailable prior to 2006 and 2001, respectively.

Conclusions — Dialysis-treated AKI survivors had greater post-discharge healthcare utilization and costs vs. hospitalized controls. Strategies are needed to improve follow-up care for children after dialysis-treated AKI to prevent long-term complications.