Effect of dialysis initiation for preemptively listed candidates in the revised kidney allocation policy

The new allocation policy for deceased donor kidneys in the United States is expected to begin in late 2014. As part of this policy, prioritization to the highest quality deceased donor kidneys is dependent on candidate's estimated posttransplant survival (EPTS) score. In particular, candidates with low (≤20%) EPTS (indicating better estimated survival) will have greater access to donor offers. We evaluated the effect of dialysis initiation on preemptively listed candidates' EPTS score. Using current estimates, approximately 10% (n = 19,406) of candidates placed on the waiting list between 2008 and 2013 were listed preemptively and would have qualified for top 20% status. These patients were more likely younger, female, Caucasian and nondiabetic compared to other candidates. Among nondiabetic preemptively listed candidates, dialysis initiation decreases EPTS score (indicating better estimated survival and higher allocation priority) for approximately 5 months. In contrast, diabetic patients' EPTS score significantly increases (approximately 6%) immediately upon dialysis initiation. Our results reveal a counterintuitive aberration in the EPTS formula, which is important for decision making regarding organ selection and timing of dialysis initiation in the new allocation system. Revision of the EPTS formula should be considered to address these findings and further understanding of the impact of the new allocation system on candidates' prognosis is important.