title: Mortality reduction by post-dilution online-haemodiafiltration: a cause-specific analysis.
abstract: From an individual participant data (IPD) meta-analysis from four randomized controlled trials comparing haemodialysis (HD) with post-dilution online-haemodiafiltration (ol-HDF), previously it appeared that HDF decreases all-cause mortality by 14% (95% confidence interval 25; 1) and fatal cardiovascular disease (CVD) by 23% (39; 3). Significant differences were not found for fatal infections and sudden death. So far, it is unclear, however, whether the reduced mortality risk of HDF is only due to a decrease in CVD events and if so, which CVD in particular is prevented, if compared with HD.
  
  
  
  The IPD base was used for the present study. Hazard ratios and 95% confidence intervals for cause-specific mortality overall and in thirds of the convection volume were calculated using the Cox proportional hazard regression models. Annualized mortality and numbers needed to treat (NNT) were calculated as well.
  
  
  
  Besides 554 patients dying from CVD, fatal infections and sudden death, 215 participants died from 'other causes', such as withdrawal from treatment and malignancies. In this group, the mortality risk was comparable between HD and ol-HDF patients, both overall and in thirds of the convection volume. Subdivision of CVD mortality in fatal cardiac, non-cardiac and unclassified CVD showed that ol-HDF was only associated with a lower risk of cardiac casualties [0.64 (0.61; 0.90)]. Annual mortality rates also suggest that the reduction in CVD death is mainly due to a decrease in cardiac fatalities, including both ischaemic heart disease and congestion. Overall, 32 and 75 patients, respectively, need to be treated by high-volume HDF (HV-HDF) to prevent one all-cause and one CVD death, respectively, per year.
  
  
  
  The beneficial effect of ol-HDF on all-cause and CVD mortality appears to be mainly due to a reduction in fatal cardiac events, including ischaemic heart disease as well as congestion. In HV-HDF, the NNT to prevent one CVD death is 75 per year.
authors.affiliation: Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Menso J
authors.initials: MJ
authors.lastname: Nubé
authors.affiliation: The George Institute for Global Health, University of Oxford, Oxford, UK.|Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Sanne A E
authors.initials: SAE
authors.lastname: Peters
authors.affiliation: Department of Nephrology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Blankestijn
authors.affiliation: Centre of Medical Excellence, Fresenius Medical Care Deutschland, Bad Homburg, Germany.|Dialysis Research and Training Institute, Montpellier, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Canaud
authors.affiliation: University College London, Centre for Nephrology, Royal Free Hospital, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
authors.affiliation: Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Muriel P C
authors.initials: MPC
authors.lastname: Grooteman
authors.affiliation: Division of Nephrology, Ege University School of Medicine, Izmir, Turkey.
authors.forename: Gulay
authors.initials: G
authors.lastname: Asci
authors.affiliation: Department of Nephrology, Alessandro Manzoni Hospital, Lecco, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Locatelli
authors.affiliation: Nephrology Department, Hospital Clinic, Barcelona, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Maduell
authors.affiliation: Dialysis Research and Training Institute, Montpellier, France.|Biochemistry and Hormonology Department, CHU, PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR 9214, Montpellier, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Morena
authors.affiliation: Division of Nephrology, Ege University School of Medicine, Izmir, Turkey.
authors.forename: Ercan
authors.initials: E
authors.lastname: Ok
authors.affiliation: Biostatistics Unit, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.|Biostatistics and Data Management Platform, IDIBAPS, Hospital Clinic, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Torres
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Michiel L
authors.initials: ML
authors.lastname: Bots
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D018481:Convection; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009026:Mortality; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D006435:Renal Dialysis
keywords: cardiovascular disease; convection volume; haemodiafiltration; meta-analysis; mortality