The IDEAL trial in Australia and New Zealand: Clinical and Economic impact.

Background The impact of research findings on clinical practice usually remains uncertain and unmeasured. To address this problem, we examined the long term clinical and economic impact of the Initiating Dialysis Early and Late (IDEAL) study, using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Methods We performed a registry-based study including all incident adult dialysis patients in Australia and New Zealand from July 2000-June 2018. A piecewise-linear regression model was used to examine differences in mean estimated Glomerular Filtration Rate (eGFR) at dialysis commencement for the years prior (2000-2010) and following (2010-2018) publication of the IDEAL results. The Return on Investment (ROI) was calculated using the total cost of performing the IDEAL study and the cost or savings accruing in Australia and New Zealand from change in dialysis initiation practice. Results From July 2000-June 2010, mean eGFR at dialysis commencement increased at a rate of 0.21 mL/min/1.73m2 per year (95% CI 0.19 to 0.23). After IDEAL results were published, mean eGFR at dialysis commencement did not show any temporal change (-0.01 mL/min/1.73m2 per year, 95% CI -0.03 to 0.01). The ROI of the IDEAL study was AUD $35.70 per AUD $1 spent, an estimated saving to Australian and New Zealand health systems of up to AUD $84M per year. Conclusions The previous trend to higher eGFR at dialysis commencement changed following publication of IDEAL results to a steady eGFR which has continued for a decade, avoiding unnecessary dialysis treatments and accruing savings to Australian and New Zealand health systems.