1012

Abstract

Introduction: Renal replacement therapy (RRT) for critically ill patients with acute kidney injury (AKI) can be provided by continuous (CRRT) or intermittent (IRRT) modalities. Neither modality has shown superiority in terms of survival whilst dialysis dependence among survivors remains a significant medical and economic issue. A recent meta-analysis found initial treatment with IRRT was associated with higher risk of dialysis dependence than CRRT. Methods: We performed a cost-utility analysis comparing initial CRRT vs. initial IRTT in AKI. Our analysis assumed a pool of patients who would potentially be eligible for either modality. We modeled Life-Years Gains (LYG), Quality-adjusted Life Years (QALYs) gains and healthcare costs over a lifetime horizon, discounted at 5%. A Markov model with two health states for survivors was designed: dialysis dependence and dialysis independence. The model has daily cycle over the 5 first years after RRT initiation and yearly cycle afterwards. We applied Weibull regression from published estimates to fit survival curves for CRRT and IRRT patients and to fit the proportion of dialysis dependence among CRRT survivors. We then applied the risk ratio reported in the meta-analysis to the fitted CRRT estimates in order to determine the proportion of dialysis dependence for IRRT survivors. We conducted sensitivity analyses based on a range of differences for daily implementation cost between CRRT and IRRT (base case: CRRT day $500 more expensive than IRRT day; range from $250 to $1,000) and a range of risk ratios for dialysis dependence between CRRT and IRRT (from 1.20 to 3.00; base case: 1.99). Results: CRRT was associated with a marginally greater gain in QALYs as compared with IRRT (1.617 vs. 1.584). Despite higher hospitalization and ICU costs for CRRT ($82,283 for CRRT vs. $79,342 for IRRT), the lifetime time cumulative total cost including the cost of dialysis dependence was lower for CRRT ($109,742 for CRRT vs. $116,901 for IRRT). The base case incremental cost-effectiveness analysis showed CRRT dominated IRRT in health economic terms. Conclusions: Initial CRRT is cost-effective as compared to initial IRRT by reducing the rate of long-term dialysis dependence among critically ill AKI survivors.