Likelihood of lung transplantation before and after introduction of the lung composite allocation score

Continuous distribution (CD), implemented in March 2023, marked the most substantial revision to United States (U.S.) lung allocation since the lung allocation score (LAS) was introduced in 2005. We evaluated whether inequities observed under LAS changed after CD.

We conducted a retrospective study of 5887 adult candidates listed for lung transplant in the U.S. during the pre-CD (March 8, 2021-March 8, 2022) and post-CD (March 9, 2023-March 8, 2024) eras using Organ Procurement and Transplantation Network data. Multivariable competing risk models identified factors associated with the 1-year cumulative incidence of lung transplant.

Pre-CD, blood type O (sHR, 0.83; 95%CI, 0.76-0.91), female birth sex (sHR, 0.69; 95%CI, 0.61-0.78), and listing in the Northeast (sHR, 0.75; 95%CI, 0.67-0.85) were associated with lower likelihood of transplant. Post-CD, younger age at listing (per 5-year decrease; sHR, 1.03; 95%CI, 1.01-1.06) and listing in the West (sHR, 1.17; 95%CI, 1.05-1.30) were associated with higher likelihood of transplant. Additionally, post-CD, diagnosis group B (sHR, 0.69; 95%CI, 0.55-0.87) and D (sHR, 0.86; 95%CI, 0.78-0.94), blood type O (sHR, 0.66; 95%CI, 0.60-0.72), and shorter stature (per 5 cm decrement; sHR, 0.91; 95%CI, 0.88-0.94) were associated with lower likelihood of transplant.

CD altered factors associated with lung transplantation in the U.S. Younger age was associated with higher likelihood of transplant, and sex-based disparities diminished under the CAS. However, disadvantages for blood type O and short stature persist under CAS. Ongoing policy refinement is needed to promote equity and optimize outcomes.