*PURPOSE: Under the new distance-based kidney allocation system (KAS250), transplant centers have reported increases in the volume of organ offers received and operational burden. Centers can set filters based on donor characteristics to have all their patients automatically bypassed for certain organ offers. *METHODS: We used national registry data to compare bypass filter settings in January 2021 (pre-KAS250) and December 2021 (post-KAS250). We calculated the change in each transplant center’s organ offer volume and filter settings. Organ offer volume was defined as the total number of kidney offers with a response logged per center in each month of interest. Filter setting scores were calculated as the total number of filters set open to accepting organs from donors of that type, or with settings more open/accepting than the median for continuous values (e.g. maximum donor age). The change in the proportion of offers that were automatic bypasses was also calculated, and Pearson correlations were calculated between measures. *RESULTS: Pre-KAS250, 171 included centers received and responded to a median of 11,171 (interquartile range [IQR]: 4,993-27,246) offers in January 2021. In December 2021, centers received and responded to a median of 16,698 (IQR: 7,798-39,812) offers, corresponding to a median increase in offer volume of 44% (IQR: 22-71%). As of 1/31/2021, centers had a median 66 (IQR: 57-74) out of 91 filters set open to receiving offers. As of 12/31/2021, centers had a median 67 (IQR: 57-75) of these filters set open to receiving offers, with a median 0% change (IQR: -1-3%) in filter openness. Change in offer volume was not correlated with change in filter settings or the proportion of declined offers that were bypasses (Figure 1). *CONCLUSIONS: Almost all centers experienced an increase in organ offer volume under KAS250. Even centers with more restrictive filter settings saw increases in offer volume and a decrease in the proportion of offer refusals that occurred via bypass. Despite large increase in organ offer volume, most centers do not appear to be making their center-wide bypass filter settings more restrictive to preemptively screen out offers they already know they will not accept. This suggests a need to redesign the bypass filters to help centers overcome the fear of missing out and manage the increased logistical burden under KAS250 in order to ensure an efficient allocation system with fewer organ discards. [

]CITATION INFORMATION: Yu M., King K., Husain S., Mohan S. Change in Organ Offer Volume and Bypass Filter Settings Under New Kidney Allocation System AJT, Volume 23, Issue 6, Supplement 1.

Miko Yu MA

Columbia University Medical Center

Appearances