EJ SEE1,2, J HEDLEY2,3, JWM AGAR2,4, CM HAWLEY2,5, DW JOHNSON2,5, PJ KELLY2,3, VW LEE2,6, K MAC2, KR POLKINGHORNE1,2, KS RABINDRANATH2,7, K SUD2,8, AC WEBSTER2,6
1Department of Nephrology, Monash Health, Clayton, Victoria; 2Australia and New Zealand Dialysis and Transplant Registry, Adelaide, South Australia; 3Sydney School of Public Health, University of Sydney, Sydney, New South Wales; 4Department of Nephrology, University Hospital Geelong, Geelong, Victoria; 5Department of Nephrology, Princess Alexandra Hospital, Woolloongabba, Queensland; 6Department of Nephrology, Westmead Hospital, Westmead, New South Wales; 7Department of Nephrology, Waikato District Hospital, Hamilton, New Zealand; 8Department of Nephrology, Nepean Hospital, Kingswood, New South Wales
Aim: To evaluate the association between haemodialysis (HD) modality and survival in the entire Australian and New Zealand incident HD patient population.
Background: There is ongoing uncertainty regarding the comparative effects of haemodiafiltration (HDF) and standard HD on patient survival. Randomized trials have reported inconsistent results, while observational studies have tended to demonstrate benefit.
Methods: Using data from the ANZDATA Registry, this cohort study examined all patients who commenced HD in Australia and New Zealand between 2000 and 2014. The primary outcome was all-cause mortality, measured from first HD treatment, and the secondary outcome was cardiovascular mortality. Outcomes were examined using multivariable Cox regression and competing risk analyses. Patients were censored at permanent discontinuation of HD or at 31 December 2014. Analyses were stratified by country.
Results: The study included 26,961 patients (4110 HDF, 22,851 standard HD) with a median follow-up of 5.57 (interquartile range 3.07-8.79) years. Patients who received HDF were more likely to be obese or diabetic, and less likely to be white or aged ≥70 years. There was no difference in cardiovascular disease or vascular access between groups. Compared to standard HD, HDF was associated with a significantly lower risk of all-cause mortality (adjusted HR for Australia 0.60, 95% CI 0.55-0.66; adjusted HR for New Zealand 0.75, 95% CI 0.68-0.82). In Australian patients, there was an association between HDF and reduced cardiovascular mortality (adjusted SHR 0.83, 95% CI 0.69-0.99).
Conclusions: Compared to standard HD, HDF was associated with superior survival in Australian and New Zealand patients. The benefit of HDF may have been heightened by longer treatment time and preferential use of permanent vascular access, both of which facilitate higher convection volumes.