Effect of centre and patient related factors on uptake of haemodiafiltration in australia and new zealand: A Cohort study using anzdata.

Background The use of haemodiafiltration (HDF) for the management of patients with end-stage kidney failure is increasing worldwide. Factors associated with HDF use have not been studied and may vary in different countries and jurisdictions. The aim of this study was to document the pattern of increase and variability in uptake of HDF in Australia and New Zealand, and to describe patient- and centre-related factors associated with its use. Methods Using the Australian and New Zealand Dialysis and Transplant Registry, all incident patients commencing haemodialysis (HD) between 2000 and 2014 were included. The primary outcome was HDF commencement over time, which was evaluated using multivariable logistic regression stratified by country. Results Of 27 433 patients starting HD, 3339 (14.4%) of 23 194 patients in Australia and 810 (19.1%) of 4239 in New Zealand received HDF. HDF uptake increased over time in both countries but was more rapid in New Zealand than Australia. In Australia, HDF use was more likely in males (odds ratio (OR) 1.13, 95% confidence interval (CI) = 1.03-1.24,P = 0.009) and less likely with older age (reference 70 years OR = 0.48; 95% CI = 0.41-0.56); higher body mass index (body mass index (BMI) < 18.5 kg/m(2)OR = 0.62; 95% CI = 0.46-0.84; 18.5-29.9 kg/m(2)reference; >30 kg/m(2)OR = 1.46; 95% CI = 1.33-1.61), chronic lung disease (OR = 0.84; 95% CI = 0.76-0.94;P < 0.001), cerebrovascular disease (OR = 0.76; 95% CI = 0.67-0.85;P < 0.001) and peripheral vascular disease (OR = 0.77; 95% CI = 0.70-0.85;P < 0.001). No association was identified with race. In New Zealand, HDF use was more likely in Maori and Pacific Islanders (OR = 1.32; 95% CI = 1.05-1.66) and Asians (OR = 1.75; 95% CI = 1.15-2.68) compared to Caucasians, and less likely in males (OR = 0.76; 95% CI = 0.62-0.94;P = 0.01). No association was identified with BMI or co-morbidities. In both countries, centres with a higher ratio of HD to peritoneal dialysis (PD) were more likely to prescribe HDF. Larger Australian centres were more likely to prescribe HDF (36-147 new patients/year OR = 26.75, 95% CI = 18.54-38.59; 17-35/year OR = 7.51, 95% CI = 5.35-10.55; 7-16/year OR = 3.00; 95% CI = 2.19-4.13; <= 6/year reference). Conclusion Haemodiafiltration uptake is increasing, variable and associated with both patient and centre characteristics. Centre characteristics not explicitly captured elsewhere explained 36% of variability in HDF uptake in Australia and 48% in New Zealand.