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Adoption of a new version of the Model for End-Stage Liver Disease, known as MELD 3.0, closed the gap in access to liver transplant between men and women, an analysis showed.

Since MELD 3.0 was implemented in July 2023, a higher proportion of women are now on the liver transplant waitlist, and waitlist mortality and transplant rates for women more closely approximate those for men, reported Allison Kwong, MD, of Stanford Health Care in Redwood City, California.

After MELD 3.0 went into effect:

• Women comprised 43.7% of new waitlist registrations compared with 40.4% before it was implemented (P<0.001)
• The 90-day waitlist dropout rate for women declined from 13.5% to 9.1% (P<0.0001)
• The percentage of women receiving a transplant increased from 37.3% to 42.1% (P<0.001)

"We can see from our data that MELD 3.0 has worked as intended and has successfully mitigated at least some disparities in waitlist outcomes and transplant access," said Kwong during a late-breaking abstract session at the American Association for the Study of Liver Diseases annual meeting in San Diego.

MELD scores range from 6 to 40, with higher scores indicating a higher risk of waitlist mortality and increased urgency for transplant, and Kwong noted that the median MELD score for women was still higher than that for men (29 and 27, respectively), "indicating that there still may be some differences in transplant access between the sexes."

Why 3.0?

Since 2002 MELD scores have been used to prioritize patients with chronic liver disease for transplantation depending on medical urgency or the risk of mortality without transplant.

"Under this system, however, there have been sex-based disparities in liver transplant that have been identified where men have a lower pre-transplant mortality and higher deceased-donor liver transplant rates compared to women," Kwong said.

These disparities were likely due to several factors, the crucial one involving creatinine, which was one of the values used to calculate the overall priority score. However, because women have less muscle than men, they do not produce equivalent volumes of creatinine -- thus making that lab test more likely to underestimate renal dysfunction in women.

Kwong also noted that disparities in MELD scores were exacerbated by height and weight differences between the sexes and a lack of size-appropriate donors, as well as disease etiology and exception points.

As incorporated in 2002, MELD had three variables -- creatinine, bilirubin, and the international normalized ratio. It was updated in 2016 to include sodium (MELD-Na).

With MELD 3.0, the Organ Procurement and Transplantation Network (OPTN) by incorporating additional variables (albumin and sex), updating coefficients for existing variables, introducing interaction terms, and lowering the maximum creatinine value from 4.0 to 3.0 mg/dL.

Session moderator Aleksander Krag, MD, PhD, of Odense University Hospital in Denmark, suggested that there could be other disparities -- such as those based on race, age, or liver disease etiology -- affecting liver transplant access. "Have you looked into this with this massive database?" he asked.

"Age and race are not in the allocation system for various reasons, and MELD does seem to predict reasonably well the risk of waitlist mortality. But ... there are certainly disparities that still exist in the system based on age and race," said Kwong. "We did look at etiology and there were no significant differences between the two eras in terms of the etiology of liver disease that we were transplanting during this time."

"It's still early to see how MELD 3.0 will serve the system," she added. "So far, so good."

For this study, the researchers used data from the OPTN, evaluating the records of 22,317 newly registered candidates for liver transplant (10,568 in the 12 months before the new policy was implemented and 11,749 in the 12 months after it was implemented), as well as 18,706 transplant recipients (8,134 pre-policy and 9,183 post-policy).

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