Background: From 2013, Australia has experienced a sustained increase in the proportion of deceased donor kidneys that are retrieved but not utilized for transplantation. We aimed to determine whether this could be explained by changes in donor characteristics over time.
Methods: Registry data were used to examine predictors of kidney nonutilization over the period 2005-2017. Multilevel mixed effect logistic regression modeling and propensity score analysis were used to determine whether era of donation (2013-2017 versus 2005-2012) was an independent predictor of organ nonutilization after controlling for donor characteristics.
Results: A total of 7810 kidneys were retrieved for the purpose of transplantation with 334 (4.3%) not utilized. The nonutilization rate was 5.8% in 2013-2017 compared to 2.7% in 2005-2012. Despite adjustment for donor characteristics, donation in the more recent era remained a significant predictor of kidney nonutilization (adjusted odds ratio, 1.98; 95% confidence interval, 1.54-2.54; P < 0.001). This finding was confirmed in the propensity score analysis.
Conclusions: Kidneys retrieved in Australia since 2013 were more likely not to be utilized for transplantation even after adjusting for changes in donor characteristics. The abrupt increase may be explained by increased clinical risk aversion, changes in unmeasured donor factors or logistical issues. Although nonutilization rates in Australia remain low by international standards, further clinical auditing of the reasons for offer decline may help to optimize resource utilization and maximize transplant opportunities.