Development of a new mortality scoring system for acute kidney injury with continuous renal replacement therapy

Aim: On the basis of the worst outcomes of patients undergoing continuous renal replacement therapy (CRRT) in intensive care unit, previously developed mortality prediction model, Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) needs to be modified.

Methods: A total of 828 patients who underwent CRRT were recruited. Mortality prediction model was developed for the prediction of death within 7 days after starting the CRRT. Based on regression analysis, modified scores were assigned to each variable which were originally used in the APACHE II and SOFA scoring models. Additionally, a new abbreviated Mortality Scoring system for AKI with CRRT (MOSAIC) was developed after stepwise selection analysis.

Results: We used all the variables included in the APACHE II and SOFA scoring models. The prediction powers indicated by C-statistics were 0.686 and 0.683 for 7-day mortality by the APACHE II and SOFA systems, respectively. After modification of these models, the prediction powers increased up to 0.752 for the APACHE II and 0.724 for the SOFA systems. Using multivariate analysis, seven significant variables were selected in the MOSAIC model wherein its C-statistic value was 0.772. These models also showed good performance with 0.720, 0.734 and 0.773 of C-statistics in the modified APACHE II, modified SOFA and MOSAIC scoring models in the external validation cohort (n = 497).

Conclusion: The modified APACHE II/SOFA and newly developed MOSAIC models could be more useful tool for predicting mortality for patients receiving CRRT.