Sex Disparities in Transplantation Access and Outcomes: An Overview

Sex disparities have been identified in rates of referral for transplant evaluation, rates of activation on the waitlist, time to transplantation, candidate survival on the waitlist, and graft and patient survival after transplant. Healthcare providers may contribute to these disparities through unconscious or conscious bias in selection of patients for transplant evaluation, activation on the waiting list, or access to life-sustaining therapies as a bridge to transplant. Both biologic differences between males and females and gendered behaviors may also contribute to sex disparities in transplant access and outcomes. This review will provide an overview of our current understanding of the magnitude and direction of sex differences at each stage of the kidney, heart, liver, and lung transplant trajectory. Potential mechanisms underlying the observed sex differences will also be considered. The combined impacts of multiple, sometimes competing, factors-including the role of selection bias on subsequent outcomes-will also be explored. Existing evidence points to restricted access to transplant for females compared with males, particularly at older ages. Sex differences in graft loss and excess mortality rates vary by donor sex and recipient age. A comprehensive understanding of the magnitude and direction of sex differences in transplantation access and outcomes is only the first step in addressing disparities. Further research is needed to determine mechanisms. A commitment from transplant professionals to achieve equitable access and outcomes is also required.