Authors' objectives:

The aim of this report was to compare and evaluate, in view of the existing evidence, the effectiveness and security of high flux hemodialysis, high efficiency hemodialysis, and of the different hemodiafiltration techniques. We also aimed to assess if any of the hemodialysis modalities offered additional advantages to subgroups of patients with specific characteristics, specially in relation to mortality, morbidity and quality of life.

Authors' results and conclusions: 35 original articles met the inclusion/exclusion criteria: 18 compared high flux hemodialysis with low flux hemodialysis, one compared high efficiency hemodialysis with low flux hemodialysis, 13 different modalities of HDF with high or low flux hemodialysis and 3 different techniques of HDF. The largest randomized, controlled trial (HEMO study) found that high flux dialysis reduced in 8% the risk of death from any cause (p=0,23) and in 10% the risk of hospitalization and death from cardiac causes (p< 0,05). Two retrospective studies showed significant reductions in death and morbility for high flux dialysis. One cross-over clinical trial established improvements in the quality of life and cardiovascular stability. The results were concordant in that high flux hemodialysis reduced b2-microglobulin but only one study reported that it postponed clinical manifestations of amyloidosis. The results on the effects of high flux hemodialysis on anemia, nutritional status and cardiovascular risk factors when patients were adequately treated and controlled, were conflicting. The studies that evaluated different HDF modalities agreed on the fact that it did not offer advantages on morbility or nutritional status. The only study that offered mortality results did not find differences between HDF and high or low flux dialysis. HDF reduced b2-microglobulin post-dialysis levels but not pre-dialysis levels. The results of the studies designed to assess the effects of acetate-free biofiltration and on line biofiltration on anemia showed contradictory results on patients treated and not treated with rHuEpo. According to the results derived from the quality scale specifically developed to evaluate dialysis techniques, only one study, the HEMO study scored above 75%.

Authors' recommendations: The evidence available suggests that high flux dialysis reduces mortality in comparison to low flux dialysis, but in the only adequately designed study (HEMO study) found that these differences were not significant. High flux dialysis reduces b2-microglobulin levels in relation to low flux dialysis but there is not sufficient evidence to determine the effect on amyloidosis. In view of the existing evidence, the different HDF modalities do not seem to offer significant benefits in relation to hemodialysis performed with biocompatible membranes. Even though some studies suggest that on-line HDF and acetate-free biofiltration might benefit patients treated with rHuEpo, the methological flaws of the studies do not allow for definite conclusions on this aspect. The available studies do not enable us to know the effectiveness of the different dialysis techniques at long term or in critical patients. All of the modalities of dialysis evaluated are safe.

Authors' methods: Systematic review

Project Status: Completed

Year Published: 2005

URL for published report: http://avalia-t.sergas.es/DXerais/526/INF200503Hemo.pdf

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Spain

Organisation Name: Scientific Advice Unit, avalia-t; The Galician Health Knowledge Agency (ACIS)

Contact Address: Conselleria de Sanidade, Xunta de Galicia, San Lazaro s/n 15781 Santiago de Compostela, Spain. Tel: 34 981 541831; Fax: 34 981 542854;

Contact Name: avalia-t@sergas.es

Contact Email: avalia-t@sergas.es

Copyright: <p>Galician Agency for Health Technology Assessment (AVALIA-T)</p>