7/2/2023 0 Comments Meld score rangeAkin to Kaplan-Meier, the Aalen-Johansen curves give an accurate view of the outcomes over time, however they can only be fit using baseline covariates, thus the impact of MELD fluctuations on the waitlist cannot be assessed.įigure 1A. Alternatively, their mortality may be affected by factors inherently associated to the female sex (ie, lower incidence of HCC, different MELD score progression after listing). The results of this regression model are shown in the Table included under the graph in Figure 1A. For example, it can examine the question if women are less likely to undergo LT because a) female sex is an independent risk factor for LT, or b) women are more likely to die or be removed from the list, thus their lower likelihood of LT is an indirect consequence of higher waitlist mortality or removal. Additionally, the Putter method allows to examine how a certain predictor of interest (ie, sex) impacts each of the competing risks and thus, is able to analyze how disparities in one outcome (ie, LT) influence the other (ie, death). The curves are stratified by the following covariates at the time of listing: calculated MELD score, age, UNOS region, blood type and height. To illustrate the rates of outcomes, we used Aalen-Johansen curves ( Figure 1A), which are an extension of Kaplan-Meier curves when more than 2 outcomes are possible. In this study we explored i) differences and determinants of waitlist mortality and liver transplantation rates between men and women ii) the impact of renal function underestimation based on serum creatinine use in MELD score in disparities to liver transplantation and iii) whether correction of deficient MELD points improves women’s deficit in liver transplantation.Įxploring factors that impact LT disparities between men and womenĬompeting risk analysis based on cause-specific hazards (methods of Putter et al) 15, 16 was used to assess the rates of 3 outcomes: death, removal and LT. A more detailed examination of the factors contributing to the disparities is required to guide strategies for an impartial allocation of this very limited lifesaving resource. More importantly, it is unclear if women’s higher risk of death while waiting for a liver graft is related to lower access to transplantation, or to biological reasons associated with female sex, inaccurately captured by the MELD score. Patients who develop HCC are given extra MELD score points (‘exception points’) in order to facilitate access to LT for patients with HCC in whom their biological MELD score alone does not represent the urgency in the need for LT. Differences in liver disease etiology and progression (predominantly hepatitis C and alcoholic liver disease in men primary biliary cholangitis predominance in women) 12, 13, as well as the incidence of hepatocellular carcinoma (HCC) 14 are factors that have not been accounted for in previous studies. The disparities in LT between sexes are likely multifactorial and extend beyond height and listing MELD score 11. Height contributes, but does not entirely explain the disparities in wait list mortality and access to LT between men and women 3. Women have smaller body size, which may limit the acceptability of a potential liver allograft if the available organ comes from a larger individual 9, 10. However, no study was able to show that sex-adjustment of MELD score would eliminate this inequity 8. One proposed factor was a systematic bias in MELD score, which disadvantages women given their lower muscle mass and, consequently, their serum creatinine 5, 6, 7. The disparity in liver transplantation rates between men and women have been examined in various analyses, and several contributing factors have been speculated. Population-based studies showed that women are at a disadvantage through all stages in the process of transplant evaluation, from diagnosis of liver disease to enrollment on the waiting list 4. Furthermore, in the MELD era women are more likely than men to die while waiting for a donor organ 1, 2, 3. ![]() Women are 30% less likely to undergo LT and the disparity has increased after the introduction of MELD-based allocation system 1. Sex-based disparities in liver transplantation (LT) have been recognized but not well understood.
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