A comparison of patient survival on haemodiafiltration and standard haemodialysis: A binational inception cohort study using the australia and new zealand dialysis and transplant registry.

Introduction and Aims: It is unclear if haemodiafiltration (HDF) improves patient survival compared to standard haemodialysis (HD). Observational studies have tended to show benefit with HDF, while meta-analyses have not provided definitive proof of superiority. This study aimed to evaluate the association between HD modality and survival in the entire Australian and New Zealand incident HD patient population. Method(s): Using data from the ANZDATA Registry, this binational inception 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 and competing risk regression analyses. Patients were censored at permanent discontinuation of HD or at 31 December 2014. Analyses were stratified by country. Result(s): 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 (p<0.001) or diabetic (p<0.001), and less likely to be white (p<0.001) or aged >70 years (p<0.001). There were no differences in pre-existing cardiovascular disease (p=0.3) or vascular access (p=0.2) between groups. Compared to standard HD, HDF was associated with a significantly lower risk of all-cause mortality (adjusted HR for Australia 0.63,95% CI 0.57-0.68; adjusted HR for New Zealand 0.74, 95% CI 0.70-0.79). In Australian patients, there was an association between HDF and reduced cardiovascular mortality (adjusted SHR 0.83,95% CI 0.69-0.99). Conclusion(s): Compared tostandard HD, HDF was associated with superior survival in Australian and New Zealand patients.