Acute Kidney Disease Staging Based on Estimated Glomerular Filtration Rate Predicts Outcomes Better than Staging Based on Serum Creatinine in Patients with Dialysis-Requiring AKI

[[abstract]]Background: The comparative performance of two staging systems for acute kidney disease (AKD), designated AKDeGFR and AKDsCr, remains uncertain. Our objective is to assess the predictive ability of these staging systems concerning outcomes. Methods: This population-based retrospective observational cohort study identified 71,289 hospitalized patients with acute kidney injury requiring dialysis between July 1, 2015, and June 30, 2022, in the Taiwan National Health Insurance Research Database. AKD stages were defined according to the ADQI 16 Workgroup (AKDsCr) and 2021 KDIGO Consensus (AKDeGFR). Cox proportional hazard models were constructed to examine associations between AKD stages and outcomes including mortality and sustained renal recovery. Results: The AKDeGFR staging system predicted both outcomes better than the AKDsCr staging system (Figure 1). Hazard ratios and 95% confidence intervals for mortality across increasing AKDeGFR stages were 1.27 (1.18 - 1.36), 1.70 (1.59 - 1.82), 2.49 (2.35 - 2.64), 2.96 (2.78 - 3.15), and 5.22 (5.02 - 5.43). Conversely, within the AKDsCr staging system, hazard ratios and 95% confidence intervals for mortality across ascending stages were 1.00 (0.93 - 1.07), 1.00 (0.91 - 1.10), 0.93 (0.81 - 1.07), and 3.37 (3.27 - 3.46). Subgroup and sensitivity analyses yielded consistent results. Conclusion: 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.