title: Convective versus diffusive dialysis therapies for chronic kidney failure: an updated systematic review of randomized controlled trials.
abstract: BACKGROUND
  Convective dialysis therapies (hemofiltration or hemodiafiltration) are associated with lower mortality compared to hemodialysis in observational studies. A previous meta-analysis of randomized trials comparing convective modalities with hemodialysis in 2006 was inconclusive due to insufficient data. Additional randomized trials recently have reported conflicting results.
  
  
  METHODS
  Systematic review and meta-analysis of randomized trials to February 27, 2013.
  
  
  METHODS
  Patients with chronic kidney failure treated by hemodialysis, hemodiafiltration, hemofiltration, or biofiltration.
  
  
  METHODS
  Randomized controlled trials.
  
  
  METHODS
  Convective therapies (hemodiafiltration, hemofiltration, and acetate-free biofiltration) compared with hemodialysis.
  
  
  RESULTS
  All-cause and cardiovascular mortality, nonfatal cardiovascular events, hospitalization, change in dialysis modality, health-related quality of life, adverse events, blood pressure, and clearances of urea and β2-microglobulin.
  
  
  RESULTS
  35 trials (4,039 participants) were included. In low-quality evidence, convective dialysis had little or no effect on all-cause mortality (relative risk [RR], 0.87; 95% CI, 0.70-1.07) and may reduce cardiovascular mortality (RR, 0.75; 95% CI, 0.58-0.97) and hypotension (RR, 0.72; 95% CI, 0.66-0.80) during dialysis, but had uncertain effects on nonfatal cardiovascular events (RR, 1.14; 95% CI, 0.85-1.52) and hospitalization (RR, 1.21; 95% CI, 0.12-12.05). Adverse events were not reported systematically and health-related quality-of-life outcomes were sparse. Convective therapies reduced predialysis levels of β2-microglobulin (mean difference, -5.77 [95% CI, -10.97 to -0.56]mg/dL) and increased dialysis dose (Kt/Vurea mean difference, 0.10; 95% CI, 0.02-0.19), but these effects were very heterogeneous. Sensitivity analyses limited to trials comparing hemodiafiltration with hemodialysis showed similar results.
  
  
  CONCLUSIONS
  Studies had important risks of bias leading to low confidence in the summary estimates and generally were limited to patients who had adequate dialysis vascular access.
  
  
  CONCLUSIONS
  Treatment effects of convective dialysis are unreliable due to limitations in trial methods and reporting. Convective dialysis may reduce cardiovascular but not all-cause mortality, and effects on nonfatal cardiovascular events and hospitalization are inconclusive.
authors.affiliation: Department of Nephrology, "Gr. T. Popa" University of Medicine and Pharmacy, Iasi, Romania; European Renal Best Practice Methods Support Team, Ghent University Hospital, Ghent, Belgium.
authors.forename: Ionut
authors.initials: I
authors.lastname: Nistor
authors.affiliation: Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand.
authors.forename: Suetonia C
authors.initials: SC
authors.lastname: Palmer
authors.affiliation: School of Public Health, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Craig
authors.affiliation: Diaverum Medical Scientific Office, Lund, Sweden.
authors.forename: Valeria
authors.initials: V
authors.lastname: Saglimbene
authors.affiliation: Consorzio Mario Negri Sud, S. Maria Imbaro, Chieti, Italy.
authors.forename: Mariacristina
authors.initials: M
authors.lastname: Vecchio
authors.affiliation: Department of Nephrology, "Gr. T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
authors.forename: Adrian
authors.initials: A
authors.lastname: Covic
authors.affiliation: School of Public Health, University of Sydney, Sydney, New South Wales, Australia; Diaverum Medical Scientific Office, Lund, Sweden; Consorzio Mario Negri Sud, S. Maria Imbaro, Chieti, Italy. Electronic address: strippoli@negrisud.it.
authors.forename: Giovanni F M
authors.initials: GF
authors.lastname: Strippoli
mesh_terms: D017583:Hemodiafiltration; D006440:Hemofiltration; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D006435:Renal Dialysis; D016896:Treatment Outcome; D014508:Urea / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D001613:beta 2-Microglobulin; D014508:Urea
keywords: End-stage kidney disease; dialysis; hemodiafiltration; meta-analysis; systematic review