Related Experiment Video
Updated: Feb 5, 2026
Competing-Risk Nomogram for Predicting Cancer-Specific Survival in Multiple Primary Colorectal Cancer Patients after Surgery
Published on: September 27, 2024
The impact of simultaneous batch turn downs and targeted kidney utilization decisions on patient survival
Diwakar Gupta1, Jingyao Huang2, Paola Martin3
1McCombs School of Business, University of Texas, Austin, Texas, United States of America.
Abstract:
In the US, Organ Procurement Organizations (OPOs) procure deceased-donor kidneys, whereas Transplant Programs (TxPs) make utilization decisions for candidates listed at their centers. For each donor, candidates are ranked in a strict priority sequence determined by the national allocation rules. Higher-ranked candidates have the right of first refusal over lower-ranked candidates. TxPs are expected to utilize kidneys based on the merits of performing a transplant for each candidate independently of other candidates. However, they frequently utilize kidneys for lower-ranked candidates. This phenomenon is called list diving. The prevalence of list diving has been documented in the literature but its impact on post-transplant outcomes has not been studied. Moreover, all of the reasons why TxPs exercise list diving are not observed in archival data. Therefore, we examine whether utilization decisions that occur either before or concurrently with multiple declines (referred to as batch turn downs) of higher-ranked candidates result in higher recipient and graft survival after accounting for treatment endogeneity. The out-of-sequence transplants identified via the time-based criterion are referred to as targeted placements (TPs). Such transplants signal TxPs' exercise of clinical judgment. We find that TPs reduce the waiting time for recipients (average time to transplant: 2.20 years for TP recipients vs. 2.64 years for non-targeted recipients, p-value < 0.01) while lengthening it for skipped candidates (average wait time until the first offer: 1.64 years for skipped candidates vs. 1.37 years for non-skipped candidates, p-value < 0.01). However, TPs do not significantly improve the survival chances of recipients in aggregate, despite the shortened waiting time. Concurrently, TPs prolong skipped candidates' waiting time and the extra wait does not improve survival chances of those among them who eventually receive transplants.
Insights
Transplant Programs (TxPs) sometimes bypass higher-ranked candidates for deceased-donor kidneys, a practice called "list diving." While this reduces wait times for some recipients, it doesn't improve overall survival and lengthens waits for others.
Area of Science:
- Nephrology
- Transplant Surgery
- Health Services Research
Background:
- Organ Procurement Organizations (OPOs) and Transplant Programs (TxPs) manage deceased-donor kidney allocation in the US.
- National rules prioritize candidates, granting higher-ranked individuals right of first refusal.
- TxPs sometimes transplant lower-ranked candidates, termed 'list diving,' a practice whose impact on outcomes is understudied.
Purpose of the Study:
- To investigate the impact of 'list diving,' specifically 'targeted placements' (TPs), on post-transplant recipient and graft survival.
- To analyze whether utilization decisions preceding or concurrent with multiple high-priority candidate declines improve outcomes.
- To account for treatment endogeneity in assessing the effects of TPs.
Main Methods:
- Analysis of archival data on deceased-donor kidney utilization decisions.
- Identification of 'targeted placements' (TPs) using a time-based criterion, signifying TxP clinical judgment.
- Statistical methods to account for treatment endogeneity when comparing outcomes.
Main Results:
- Targeted placements (TPs) significantly reduce waiting time for recipients (2.20 vs. 2.64 years, p<0.01).
- TPs lengthen waiting time for higher-ranked, skipped candidates (1.64 vs. 1.37 years, p<0.01).
- TPs do not significantly improve aggregate recipient or graft survival despite reduced waiting times.
Conclusions:
- Targeted placements shorten wait times for some kidney transplant recipients but do not enhance overall survival.
- The practice prolongs wait times for skipped candidates without improving their long-term survival prospects.
- Further research may be needed to understand the full implications of TxP clinical judgment in kidney allocation.
Related Concept Videos
01:45Kidney Structure
01:20Decision Making
Automatic decision-making is fast, intuitive, and relies on gut feelings...
01:18Survival Curves
The Kaplan-Meier estimator is the most common method for constructing survival curves. This...
01:19Survival Tree
Building a Survival Tree
Constructing a...
01:19Impact of Groups on Groups
01:09Decision Making: P-value Method
First, a specific claim about the population parameter is proposed. The claim is based on the research question and is stated in a simple form. Further, an opposing statement to the claim is also stated. These statements can act as null and alternative hypotheses: a null hypothesis would be a neutral statement while the alternative hypothesis can...