Comparison of Acute Kidney Disease Staging by Estimated Glomerular Filtration Rate and by Serum Creatinine Ratio in Patients With Dialysis-requiring Acute Kidney Injury: A National Cohort Study From Taiwan.

RATIONALE &

OBJECTIVE

The comparative performance of 2 staging systems for acute kidney disease (AKD), based on estimated glomerular filtration rate (AKDeGFR) or serum creatinine ratio (AKDsCr), remains uncertain. Our objective is to assess the predictive ability of these staging systems concerning outcomes.

STUDY

DESIGN

Population-based retrospective observational cohort study.

SETTING &

PARTICIPANTS

In total, 40,849 hospitalized patients with acute kidney injury requiring dialysis between July 1, 2015 and June 30, 2022, in the Taiwan National Health Insurance Research Database.

TESTS COMPARED: AKD stages were defined according to the Acute Dialysis Quality Initiative 16 Workgroup (AKDsCr) and 2021 Kidney Disease: Improving Global Outcomes Consensus (AKDeGFR). Cox proportional hazard models were constructed to examine associations between AKD stages and outcomes.

OUTCOMES: Mortality and sustained kidney recovery.

RESULTS

The AKDeGFR staging system predicted both outcomes better than the AKDsCr staging system. Hazard ratios and 95% confidence intervals for mortality across increasing AKDeGFR stages were 1.29 (1.19-1.41), 1.78 (1.65-1.92), 2.68 (2.49-2.87), 3.11 (2.84-3.42), and 6.34 (6.07-6.63). Conversely, within the AKDsCr staging system, hazard ratios and 95% confidence intervals for mortality across ascending stages were 0.84 (0.75-0.94), 0.90 (0.77-1.04), 0.93 (0.75-1.16), and 4.32 (4.18-4.47). Subgroup and sensitivity analyses yielded consistent results.

LIMITATIONS: Retrospective analysis based on a claims database.

CONCLUSIONS

We conclude that the AKDeGFR staging system performs better than the AKDsCr staging system in patients with acute kidney injury requiring dialysis regarding all-cause mortality and kidney recovery. Future investigations are warranted to evaluate the comparative efficacy in patients with acute kidney injury not requiring dialysis.