Influence of the Composite allocation Score on racial/ethnic disparities in lung transplantation waitlist outcomes

We examined the influence of the March 2023 Composite Allocation Score (CAS) policy change on lung transplantation (LT) versus waitlist death/deterioration by candidate race/ethnicity.

We identified LT candidates listed from 2020 to 2024 in the United Network for Organ Sharing database. Candidates were categorized by race/ethnicity (White, Black, Hispanic, or Asian). LT versus waitlist death/deterioration was compared across racial/ethnic groups for candidates listed pre-versus post-CAS. Multivariable competing risk regression, including an interaction term for CAS evaluated whether CAS modified the association between race/ethnicity and waitlist outcomes. Separate competing risk models assessed whether disparities persisted post-CAS.

Of 12,478 candidates listed for LT (median age = 63 years; 59.3% men; 71.5% White, 10.3% Black, 14.3% Hispanic, and 3.9% Asian), 9058 candidates were listed pre-CAS and 3420 post-CAS. Post-CAS, the proportion of LT within 6 months increased significantly for Hispanic candidates (80.9% vs 66.8%; P < .001), whereas waitlist death/deterioration decreased for White (3.7% vs 5.8%; P < .001), Black (4.1% vs 7.5%; P = .042), and Hispanic (4.8% vs 8.8%; P < .001) candidates. Competing risk analyses revealed that pre-CAS, Black (subdistribution hazard ratio, 0.88; 95% CI, 0.81-0.95; P = .001), Hispanic (subdistribution hazard ratio, 0.88; 95% CI, 0.82-0.95; P = .001), and Asian (subdistribution hazard ratio, 0.84; 95% CI, 0.75-0.95; P = .006) candidates had significantly lower likelihoods of LT compared with White candidates. Interaction term analysis revealed a greater post-CAS increase in LT likelihood for Hispanic compared with White candidates (interaction subdistribution hazard ratio, 1.23; 95% CI, 1.08-1.39; P = .002). Post-CAS, no significant disparities in waitlist outcomes remained between racial/ethnic groups.

CAS implementation was associated with improved LT access for Hispanic candidates. Race/ethnicity does not predict risk of LT or waitlist death/deterioration in the post-CAS era.