Purpose of review Transplantation is the life-saving therapy for patients suffering from end-organ failure, and as such, equitable access to transplantation (ATT) is of paramount importance. Unfortunately, gender/sex-based disparities exist, and despite the transplant community's awareness of this injustice, gender/sex-based disparities have persisted for more than two decades. Importantly, no legislation or allocation policy has addressed inequity in ATT that women disproportionately face. In fact, introduction of the model for end-stage liver disease-based liver allocation system in 2002 widened the gender disparity gap and it continues to be in effect today. Moreover, women suffering from kidney disease are consistently less likely to be referred for transplant evaluation and subsequently less likely to achieve a kidney transplant, yet they comprise the majority of living kidney donors. Recent findings Acknowledging gender/sex-based disparities in ATT is the first step toward interventions aimed at mitigating this long-standing injustice in healthcare. Summary This article provides a background of end-stage liver and kidney disease in women, summarizes the existing literature describing the issue of gender disparity in ATT, and identifies potential areas of intervention and future investigation.

There are approximately 125,000 newly reported cases of end-stage renal disease (ESRD) annually in the United States, with nearly 750,000 prevalent cases (1). However, only 13.7% are actively listed for kidney transplantation, despite improvements in survival, quality of life, and economic savings compared with dialysis (1-7). Listing for transplant requires a thorough psychosocial and medical assessment-including evaluation for obesity-that precludes many from pursuing transplant.The rising obesity epidemic, in which 50% of US adults are projected to live with obesity and nearly 25% will live with severe obesity by 2030, has significant implications for ESRD patients with obesity (8).

For patients with end-stage liver disease (ESLD), liver transplant is the only life-saving therapy. Given the ongoing organ shortage, a Model for End-stage Liver Disease (MELD)-based allocation was introduced in 2002 to ensure that the sickest patients were offered transplant first. MELD is a calculation based on objective laboratory data, including serum creatinine level, associated with 90-day mortality among patients with ESLD. Despite the goal of defining an objective, equitable measure of disease severity, MELDbased allocation inadvertently introduced sex-based disparities in liver transplant, with women experiencing higher wait list mortality and lower likelihood of transplant compared with men. 1 These sex-based disparities may be the result of including serum creatinine level as a measure of renal dysfunction in MELD. Importantly, serum creatinine level has been demonstrated to vary significantly based on differences in muscle mass, and not surprisingly, women tend to have lower serum creatinine levels than men, despite having the same measured kidney function (measured glomerular filtration rate). Attempts to account for this biological difference in MELD-based allocation (eg, substituting measured glomerular filtration rate for serum creatinine level) have not been widely embraced, because they would require additional testing beyond simple blood draws and be difficult to update in real time. 2 The search for alternative measures that can be easily incorporated into existing allocation algorithms is greatly needed. Frailty may be the answer. It has been identified as a risk factor for wait list mortality and is associated with declining lean body mass. 3