[The timing of renal replacement therapy on mortality in patients with acute renal injury: a reanalysis of two recently published randomized control trials].

To investigate the sources of inconsistent findings between two randomized control trials["initiation strategies for renal-replacement therapy in the intensive care unit"(AKIKI trial) vs"effect of early vs delayed initiation of renal replacement therapy on mortality in critically ill patients with acute kidney injury"(ELAIN trial) ], regarding"timing of renal replacement therapy (RRT) on mortality in patients with acute kidney injury (AKI). By reanalysis of the published data, it was found that demographics, severity of primary disease and stage of AKI before initiation of RRT were quite different between AKIKI and ELAIN trials. Interestingly, similar mortalities were demonstrated in late group of ELAIN trial, both of early and late groups of AKIKI trial [all patients were classified at Kidney Disease: Improving Global Outcomes (KDIGO) classification stage 3 of AKI, P>0.05] although a significant reduction of mortality was determined in early group of ELAIN trial (KDIGO stage 2 of AKI).Therefore, it was concluded that inconsistent results were largely attributable to the heterogeneity of enrolled patients between ELAIN vs AKIKI trials, including demographics and severity of AKI(AKI stage) before initiation of RRT.