*Purpose: Reducing discard is a current focus in US transplantation of deceased donor kidneys. One cause for the discards is the avoidance of protracted cold ischemia times (CIT). Extended CIT at transplant is associated with additional risk of graft failure and patient mortality. A preference for local or low-KDRI (kidney donor risk index) organs, the endogeneity of CIT during organ allocation, and the use of provisional offers all complicate the analysis of CIT’s influence on kidney acceptance decision making.

*Methods: Using 01/2018-06/2019 UNOS data we modelled the probability of accepting an offer for a kidney after provisional acceptance. We use logistic regression (LR) that includes CIT, KDRI, and other covariates selected from literature. Endogeneity of CIT is treated by a two-stage approach.

*Results: LR results for 1.73 million provisional acceptances from 12647 donors and 108313 candidates quantify tradeoffs between CIT at the time of offer acceptance and donor-recipient characteristics. Overall, each additional hour of CIT impacts acceptance for nonlocal and local recipients (OR=0.87, OR=0.95; p < 0.001). For KDRI >1.75 (KDPI>85) kidneys, an additional hour of CIT for nonlocal and local recipients impacts acceptance with OR=0.80 (nonlocal) and OR=0.84 (local); p<0.001. The impact of an additional hour of CIT on acceptance of kidneys with KDRI <=1.75 (KDPI <= 85) is less pronounced for nonlocal offers (OR= 0.91; p < 0.001) and not significant for local offers.

*Conclusions: The current kidney allocation system broadly distributes high-KDRI organs. As CIT is accumulated in the provisional-actual acceptance process, emphasizing local placement and reducing CIT may promote uptake and reduce discard risk of high KDRI donor kidneys.

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