Date: Saturday, May 30, 2020
Session Time: 3:15pm-4:00pm
Presentation Time: 3:30pm-4:00pm
*Purpose: Candidate height contributes to transplant rate and waitlist (WL) mortality disparities seen amongst adult women liver transplant (LT) candidates. 72% of adult women on the WL had heights <166cm, below which WL mortality begins to increase dramatically. Given that adult women and men with short stature receive WL mortality benefits when they receive first offers of pediatric donor livers due to more appropriate size-matching, we hypothesized that a height-based rule superimposed upon Acuity Circles may alleviate these disparities.
*Methods: We applied Scientific Registry of Transplant Recipients data (7/2013-6/2016) towards LSAM (v2019) to simulate allocation under the two schemes: 1. OPTN May 2019 Acuity Circles, and 2. Acuity Circles+166cm, in which pediatric donor livers were preferentially offered to adults with height <166cm prior to ≥166cm after all pediatric candidates were exhausted. Both schemes were evaluated with ten simulations with results over three years. Across replications, means, minimums, and maximums were compared via matched pairs t-tests.
*Results: Versus Acuity Circles, the 166cm scheme was projected to increase transplants in adults <166cm (5,742 vs. 5,844, p<0.001) and adult women (6,417 vs. 6,498, p<0.001) and decrease transplants in adults ≥166cm (12,370 vs. 12,261, p<0.001) and adult men (11,694 vs. 11,607, p<0.001). Compared to Acuity Circles, the 166cm scheme was projected to result in no significant changes in the overall numbers of transplants for adults (18,112 vs. 18,106, p=0.58) or children (1,843 vs. 1,841, p=0.70).
Versus Acuity Circles, the 166cm scheme was projected to decrease waitlist mortality in adults <166cm (1,371 vs. 1,348, p = 0.02) and adult women (1,505 vs. 1,483, p=0.04) and increase waitlist mortality in adults ≥166cm (2,510 vs. 2,525, p=0.03) and adult men (2,376 vs. 2,391, p=0.03). Compared to Acuity Circles, the 166cm scheme was projected to result in no significant changes in overall waitlist mortality for adults (3,881 vs. 3,874, p=0.44) or children (76 vs. 76, p=0.90).
In the 166cm scheme, adult women gained 81 transplants while adult men lost 87 transplants. Under Acuity Circles, the proportion of adult men and adult women waitlist candidates transplanted over three years were 35.34 % and 33.76%, respectively. The 166cm scheme narrowed this gap in the proportion transplanted to 35.07% for adult men and 34.15% for adult women.
*Conclusions: With the 166cm height-based rule superimposed upon Acuity Circles, we project a narrowing of the gap between adult men and women in the proportion of waitlist candidates transplanted. Our study demonstrates that using physical characteristics in allocation could optimize donor-recipient size matching and serve as a mechanism to achieve parity in the gender gap seen in transplantation rates.
To cite this abstract in AMA style:Ge J, Nicholas WL, Gentry S, Lai JC. Implementing a Height Based Rule for Allocation of Pediatric Donor Livers to Adults – A Liver Simulated Allocation Model (LSAM) Study [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/implementing-a-height-based-rule-for-allocation-of-pediatric-donor-livers-to-adults-a-liver-simulated-allocation-model-lsam-study/. Accessed September 22, 2020.
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