Dialysis modality utilization patterns and mortality in older persons initiating dialysis in Australia and New Zealand

AIM: The benefits of dialysis in the older population remain highly debated, particularly for certain dialysis modalities. This study aimed to explore the dialysis modality utilization patterns between in-centre haemodialysis (ICHD), peritoneal dialysis (PD) and home haemodialysis (HHD) and their association with outcomes in older persons. METHODS: Older persons (≥75 years) initiating dialysis in Australia and New Zealand from 1999 to 2018 reported to the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry were included. The main aim of the study was to characterize dialysis modality utilization patterns and describe individual characteristics of each pattern. Relationships between identified patterns and survival, causes of death and withdrawal were examined as secondary analyses, where the pattern was considered as the exposure. RESULTS: A total of 10 306 older persons initiated dialysis over the study period. Of these, 6776 (66%) and 1535 (15%) were exclusively treated by ICHD and PD, respectively, while 136 (1%) ever received HHD during their dialysis treatment course. The remainder received both ICHD and PD: 906 (9%) started dialysis on ICHD and 953 (9%) on PD. Different individual characteristics were seen across dialysis modality utilization patterns. Median survival time was 3.0 (95%CI 2.9-3.1) years. Differences in survival were seen across groups and varied depending on the time period following dialysis initiation. Dialysis withdrawal was an important cause of death and varied according to individual characteristics and utilization patterns. CONCLUSION: This study showed that dialysis modality utilization patterns in older persons are associated with mortality, independent of individual characteristics.