Multiple risk factors link chronic kidney disease and cardiovascular disease needing surgery. However, trends in cardiac surgery incidence and outcomes thereafter are poorly known for those people presumed to be most at risk, with kidney failure (treated with dialysis or kidney transplant to ensure long term survival). Additionally, across the entire cardiac surgery population, perioperative kidney injury is a prevalent risk and may lead to permanent kidney failure in some people, yet the incidence of this is not well defined.

Data linkage between the Australian and New Zealand Society of Cardiac & Thoracic Surgeons (ANZSCTS) Cardiac Surgery Database and the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry has been undertaken (following appropriate ethical approvals and using a third party) with oversight from a project team comprising members of both Registries and other expertise. The resulting linked dataset, located and managed in SeRP, has supported a retrospective cohort study to quantify national trends for (1) people with treated kidney failure undergoing cardiac surgery and (2) the development of kidney failure following cardiac surgery.

 The solution: The linked dataset within SeRP contains all cardiac surgeries in Australia from June 2001 to December 2019, numbering 152 748, of which 3 269 are linked with an ANZDATA record from 1963 to December 2019. SeRP users from both Registries have access to this main dataset and draw from this for analysis datasets. They employ a variety of analytical techniques, appropriate to the different data structures and multiple endpoints in the study, e.g. descriptive analysis, analysis of relative risk of outcomes, and survival (time-to-event) analysis.

Initial findings have been presented at the 57th Australian & New Zealand Society of Nephrology Annual Scientific Meeting (ANZSN ASM) in October 2022, the Australian Registry ASM in November 2022 and are scheduled for presentation at the 58th ANZSN ASM in September 2023. Manuscripts are being prepared for publication in peer-reviewed journals.