Disparities in outcomes among patients on lung transplantation waitlist in Saudi Arabia

This unique pre-CAS period provided an opportunity to report a national baseline of waitlist outcomes and disparities in access to transplantation in Saudi Arabia.This unique period of centralized transplant activity provided us an opportunity to evaluate waitlist outcomes and disparities in lung access in Saudi Arabia before CAS implementation. Therefore, we conducted a retrospective cohort study that included all consecutive adult patients (aged ≥18 years) who were listed for a first-time lung-only transplant at KFSHRC between January 1, 2014, and December 31, 2023, with follow-up data until June 30, 2025. Competing risk regression was used to identify predictors of transplantation versus death or clinical deterioration.In total, 368 patients were included (median age: 45 years; 52% male). Compared with male patients, females were significantly younger (43.0 vs. 46.0 years; P =0.009) and had significantly higher rates of sensitization (calculated panel reactive antibody [cPRA] ≥50%: 28.1% vs. 9.5%, P <0.001; cPRA ≥80%: 19.128.1% vs. 2.69.5%; P <0.001). The most common blood groups were type O (48.1%), and the most common indication was restrictive lung disease (60.9%) (Supplementary Table 1). About A total of 257 patients (70%) (257 of 368) of the waitlisted patients underwent transplantation, of which 159 were male (62%) and including 98 were (females (: 38%) and 159; males (: 62%));. Further, 13.6% had died while on the waitlist, 7.9% were removed from the waitlist for other reasons, and 32 (8.7%) remained on the list. The unadjusted 1-year cumulative incidence rates of transplantation, mortality, and waitlist removal were 63.5%, 9.2%, and 5.0%, respectively (Figure 1). The median time to transplant was 118 days (IQR: 50-194 days), and was similar for females (121 days; IQR: 42-246) and males (116 days; IQR: 51-181) (P = 0.705) (Supplementary Table 2). In the multivariable Fine-Gray competing risk analysis, compared with females, male candidates had a 70% greater likelihood of undergoing transplantation (subdistribution hazard ratio [SHR]: 1.7; 95% CI: 1.23-2.36; P = 0.001). In addition, blood group O was associated with a 43% lower likelihood of transplantation (SHR: 0.43; 95% CI: 0.33-0.57; P <0.001) and a 2.2-fold greater risk of waitlist mortality (SHR: 2.2; 95% CI: 1.05-4.64; P = 0.038) (Supplementary Table 3).In terms of post-transplant outcomesFollowing transplantation, compared with males, female recipients required had significantly longer durations of mechanical ventilation (median 8.5 vs. 5.0 days; P = 0.044) ,and hospital and ICU stays as well as higher rates ofmore frequent postoperative ECMO use support (30.6% vs. 15.2%; P = 0.003), longer ICU stays (median 15.5 vs. 11.0 days; P = 0.002), and longer total hospital stays (median 37.0 vs. 29.0 days; P = 0.012)compared with males. ; The 90-day mortality was comparable between both sexes (female: 7.1%, male: 6.3%; P = 0.789) (Supplementary Table 4). The graft survival probabilities were 86% at 1 year, 72% at 3 years, and 55% at 5 years (Supplementary Figure 1). In terms of donors, more than three-fourths were male (78.6%) (median age: 41 years).Our findings revealed a relatively young candidate population in Saudi Arabia, with a disease distribution distinct from that reported in Western registries. 1 In addition, we found that reduced transplant access among female candidates and those with blood group O. These results highlight the importance of understanding regional variation in transplant candidacy and suggest that allocation policies should consider the local demographic and biological characteristics.Our finding that females are less likely to undergo lung transplantation than males is consistent with that in the literature, including the Organ Procurement and Transplantation Networkbased analysis by Riley and Lascano (2021) 2 and findings from France. 3 This disparity was after adjusting for the significantly higher rates of sensitization and shorter stature among female candidates, suggesting systemic barriers beyond clinical or anthropometric differences may have contributed to reduced access; however, the influence of other unmeasured factors cannot be excluded. This persistent sex disparity underscores the need for targeted interventions to improve sex equity in transplant access.In unadjusted analyses, fFemale recipients also experienced significantly worse early posttransplant outcomes despite comparable 90-day mortality, and this could possibly be due to These outcomes may reflect Dddonor-recipient size mismatch, which disproportionately affects females given their shorter stature relative to the predominantly male donor pool, and a a higher HLA sensitization burden.. These findings suggest that the disadvantage faced by female candidates does not end at transplantation but extends into early post-transplant recovery.The donor landscape in Saudi Arabia provides important context for interpreting our findings. Saudi Arabia faces shortages for deceased donor organs, The deceased organ donation ratewhich is remains is substantially lower (at low at 4.0 per million /population), substantially lower than that of Spain (49.4 million/populationpmp) and the United States (48.0 million/populationpmp), and the national lung transplant rate was only 1.1 per million popultaion. 4 Reported local Barriers barriers to deceased donation include confusion between brain death and coma, inconsistent ICU communication, and religious and cultural hesitancy, despite formal religious approval of organ donation. 5 These factors likely contributed to the prolonged waiting times and waitlist mortality observed, and underscorehighlight the importance of ongoing national efforts such as the Saudi Center for Organ Transplantation Proactive Detection Program 6 and digital donor registration initiatives 7 to help expand the deceased donor pool.In addition to these initiatives, future strategies that can be considered Future strategies to address donor scarcity in Saudi Arabia include further broadening the use of extended-criteria donors, 8 and through national and regional strategies. Ddonation after circulatory death. 9 A limitation of this study was that due to the retrospective study designAs a retrospective analysis, this studyit may be subject to unmeasured confounding factors. AdditionallyIn addition, the generalizability of these findings to the current national context is limited by the recent establishment of a second lung transplant program and the adoption of the CAS system.In conclusion, the current study found that there were disparities in access to lung transplantation by sex and blood group. The data from the current study provides a national pre-CAS benchmark for future studies to determine if implementation of a formal allocation system improves equity and timely access to and outcomes of transplantation in Saudi Arabia.Overall, our findings underscore the urgent need for regionally tailored allocation policies and donor expansion strategies to ensure equitable and timely access to lung transplantation.