Kidney Res Clin Pract 2019 Jun; 38(2): 159-168  
Online hemodiafiltration and mortality risk in end-stage renal disease patients: A critical appraisal of current evidence
Helmut Schiffl
Department of Internal Medicine IV, Medical Center of the University of Munich, Munich, Germany
Correspondence to: Helmut Schiffl
Department of Internal Medicine IV, Medical Center of the University of Munich, Ziemssenstr. 1, D-80336 München, Germany. E-mail:
Received: December 25, 2019; Revised: February 24, 2019; Accepted: March 10, 2019; Published online: June 30, 2019.
© The Korean Society of Nephrology. All rights reserved.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The life expectancy of end-stage renal disease patients undergoing regular hemodialysis (HD) remains significantly lower than in the general population. Reducing excess mortality by improving renal replacement options is an unmet medical need. Online post-dilution hemodiafiltration (HDF) has been promoted as the gold standard, offering improved clinical outcomes, based on numerous observational studies that suggest a reduced mortality risk and lower morbidity with HDF compared with standard HD. However, most randomized controlled trials (RCTs) have failed to demonstrate a significant beneficial effect of HDF on all-cause mortality. The effects on secondary outcomes were often negligible or absent. Unfortunately, these RCTs were characterized by a moderate to high risk of bias. In post-hoc analyses of the largest RCTs and meta-analysis of individual participant data from four RCTs, HDF patients receiving the highest convection volume consistently and dose-dependently saw superior outcomes. However, as these studies were not designed a priori to clarify this issue, and there are no indisputable mechanisms underlying reduced mortality risks, we cannot exclude the possibility that the health status of patients (with vascular access as a proxy) may affect outcomes more than the convective technique itself. There is currently insufficient evidence to support the contention that high-volume HDF confers relevant benefits to patients over standard HD. The conflicting data of published RCTs reduce confidence in the superiority of high-volume convective therapy. Hopefully, ongoing large RCTs (for example, CONVINCE) may supply an indisputable answer to the crucial question of high-volume HDF.
Keywords: Chronic kidney failure, Hemodiafiltration, Mortality


This Article

Cited By Articles
  • CrossRef (0)
  • PMC (0)
  • SCOPUS (0)

Social Network Service


Indexed/Covered by