Women in the U.S. are significantly more likely to die while waiting on a liver transplant. The results come from a large cohort study that looked at sex-based disparities among women and men who received liver donation from living and deceased donors.

"Our findings suggest that the MELD [model for end-stage liver disease] score does not accurately estimate disease severity in women and that the lack of consideration of candidate anthropomorphic and liver measurements in the current allocation system may have a greater association with the sex disparity in liver allocation than geographic factors," the researchers wrote in their study in JAMA Surgery.

In short, using geographic data may not be enough to influence the disparity. To make the organ allocation more equitable, the way end-stage liver disease is interpreted between the genders needs to be considered.

"It has been known for more than a decade that women are disadvantaged on the liver transplant waiting list, with an increased risk of death and a decreased probability of deceased donor liver transplant compared with men," wrote Dr. Elizabeth C. Verna of Columbia University Irving Medical Center in New York City and Dr. Jennifer C. Lai of the University of California San Francisco in an editorial, titled "Time for Action to Address the Persistent Sex-Based Disparity in Liver Transplant Access.” The piece appeared as a JAMA Viewpoint.

"Despite this knowledge, there has been no effective national push to implement evidence-based systematic changes and thus no improvement in waiting list outcomes for women," they wrote.

The study used data from the Scientific Registry of Transplant Recipients. Some 81,300 adults who were waiting for liver transplants between June 2013 to March 2018.were reviewed.

Of these, roughly a third (36.1%) were women. Nearly 70% were men. Most were white and the median age was approximately 55. More women than men had previous abdominal surgeries and had fewer instances of hepatocellular carcinoma. Women also had lower anthropometric and liver measurements.

Some 8,800 of the 81,300 died while on a waiting list. Deaths were split roughly 60% and 40% between men and women, respectively. However, after adjustment, females were 8.6% more likely to die while on the wait list when compared with men.

The only other variable that varied significantly when it comes to increased gender disparity was the organization of organ procurement. Anthropometric and liver metrics and laboratory MELD scores had more statistically significant correlations than geographic differences.

"Thus, size mismatch between the donor and intended recipient and incorrect assessments of liver disease severity were more strongly associated with the observed sex disparity in wait-list mortality than local supply of organs," the researchers wrote.

"We propose that a better course of action is to simultaneously address the attributes of the existing allocation system that were most strongly associated with increased sex disparities in wait list mortality and DDLT in our study: the MELD score and candidate anthropomorphic and liver measurements," the investigators wrote. "Findings from our study support such process improvement in liver allocation."