Background
The lung allocation score prioritizes candidates for a lung transplant in the United
States. As the country adopts the continuous distribution framework for organ allocation,
we must reevaluate lung allocation score assumptions to maximize transplant benefit.
Methods
We used Scientific Registry of Transplant Recipients data to study the impact of these
changes: (1) updating cohorts; (2) transitioning from 1- to 5-year posttransplant
survival; (3) using time-varying effects for non-proportional hazards; and (4) weighting
waitlist and posttransplant area under the curve differently. Models were compared
using Spearman correlations and C-statistics. The thoracic simulation allocation model
characterized transplant rates and proportions of recipient subgroups under the current
and new systems.
Results
Posttransplant areas under the curve models were estimated with recipients aged ≥12
from January 1, 2014, to December 31, 2018. All models had similar C-statistics and
Spearman correlations, indicating similar predictive performance and posttransplant
area under the curve rankings. Five-year posttransplant area under the curve across
age and diagnosis groups varied more than 1-year groups. Using the thoracic simulation
allocation model, 1- and 5-year posttransplant model under the curve models showed
similar transplant rates and recipient characteristics under the current system, but
under continuous distribution, 5-year posttransplant area under the curve resulted
in increased transplant rates with more recipients younger and in diagnosis groups
B and C.
Conclusion
Incorporating equally weighted waitlist and posttransplant models using 5-year posttransplant
survival detected the largest variability in survival under the continuous distribution
system, which could improve long-term survival in the United States.
KEYWORDS
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to The Journal of Heart and Lung TransplantationAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Development of the new lung allocation system in the United States.Am J Transplant. 2006; 6: 1212-1227
- OPTN/SRTR 2019 annual data report: lung.Am J Transplant. 2021; 21: 441-520
- Effect of the lung allocation score on lung transplantation in the United States.J Heart Lung Transplant. 2016; 35: 433-439
- How should lungs be allocated for transplant?.Semin Respir Crit Care Med. 2018; 39: 126-137
- Development of a predictive model for long-term survival after lung transplantation and implications for the lung allocation score.J Heart Lung Transplant. 2010; 29: 731-738
Organ Procurement and Transplantation Network. Update on the continuous distribution of organs project. 2020. Accessed August 1, 2021. Available at: https://optn.transplant.hrsa.gov/governance/public-comment/update-on-the-continuous-distribution-of-organs-project/.
- Organ distribution without geographic boundaries: A possible framework for organ allocation.Am J Transplant. 2018; 18: 2635-2640
- Ethical Principles in the Allocation of Human Organs.2015 (Accessed August 1, 2021. Available at:)
- Scientific Registry of Transplant Recipients: collecting, analyzing, and reporting data on transplantation in the United States.Transplant Rev (Orlando). 2013; 27: 5056
United Network for Organ Sharing. A Guide to Calculating the Lung Allocation Score. 2020. Available at: https://unos.org/wp-content/uploads/unos/Lung_Calculation.pdf
- Multiple Imputation for Nonresponse in Surveys (Vol. 81).John Wiley & Sons, 2004
- A generalized additive model approach to time-to-event analysis.Stat Model. 2018; 18: 299-321
- The c-index is not proper for the evaluation of t-year predicted risks.Biostatistics. 2019; 20: 347-357
- Validating thoracic simulated allocation model predictions for impact of broader geographic sharing of donor lungs on transplant waitlist outcomes.J Heart Lung Transplant. 2020; 39: 433-440
Scientific Registry of Transplant Recipients. Thoracic simulated allocation model guide. 2015. Accessed August 1, 2021. Available at: https://www.srtr.org/media/1201/tsam.pdf
- Impact of the lung allocation score on survival beyond 1 year.Am J Transplant. 2014; 14: 2288-2294
- Frailty phenotypes and mortality after lung transplantation: A prospective cohort study.Am J Transplant. 2018; 18: 1995-2004
- The impact of removing the donor service area (DSA) as the first unit of allocation for lungs in the United States.J Heart Lung Transplant. 2019; 38: S150
- Effect of broader geographic sharing of donor lungs on lung transplant waitlist outcomes.J Heart Lung Transplant. 2019; 38: 136-144
- Organ procurement and transplantation network; final rule.Fed Reg. 1999; 121 (42 CFR, Part): 56650-56651
OPTN Thoracic Organ Transplantation Committee. Continuous Distribution of Lungs (Concept Paper). 2019. Accessed August 1, 2021. https://optn.transplant.hrsa.gov/media/3111/thoracic_publiccomment_201908.pdf
- Extremes of age decrease survival in adults after lung transplant.Chest. 2020; 157: 907-915
- Survival after bilateral versus single lung transplantation for patients with chronic obstructive pulmonary disease: a retrospective analysis of registry data.Lancet. 2008; 371: 744-751
- Survival differences following lung transplantation among US transplant centers.JAMA. 2010; 304: 53-60
- Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation.J Heart Lung Transplant. 2021; (S1053-2498(21)02407-4)
Article info
Publication history
Published online: February 25, 2022
Identification
Copyright
© 2022 International Society for Heart and Lung Transplantation. All rights reserved.
