MELD 3.0 Reduces Sex-Based Liver Transplant Disparities

SAN DIEGO — Since the adoption of the most recent Model for End-Stage Liver Disease (MELD 3.0) scoring system by the federal Organ Procurement and Transplantation Network (OPTN) in July 2023, the gender gap in liver transplants has narrowed, according to new research.

In particular, women are now more likely to be added to the waitlist for a liver transplant, more likely to receive a transplant, and less likely to fall off the waitlist due to death.

“MELD 3.0 improved access to transplantation for women, and now waitlist mortality and transplant rates for women more closely approximate the rates for men,” said lead author Allison Kwong, MD, assistant professor of medicine and transplant hepatologist at Stanford Medicine. 

“Overall transplant outcomes have also improved year over year,” said Kwong, who presented the findings here (abstract 5002) at The Liver Meeting 2024: American Association for the Study of Liver Diseases (AASLD). 

Changes in MELD and Transplant Numbers

MELD, which estimates liver failure severity and short-term survival in patients with chronic liver disease, has been used since 2002 to determine organ allocation priority for patients in the United States awaiting liver transplantation. Originally, the score incorporated three variables: creatinine, bilirubin, and the international normalized ratio (INR). MELDNa1, or MELD 2.0, was adopted in 2016 to add sodium. 

“Under this system, however, there have been sex-based disparities” with women receiving lower priority scores despite similar disease severity, said Kwong. 

“This has been attributed to several factors, such as the creatinine term in the MELD score underestimating renal dysfunction in women, height and body size differences, and differences in disease etiology, and how we’ve assigned exception points historically,” she reported. 

Men have had a lower pretransplant mortality rate and higher deceased donor transplant rates, she added. 

As previously reported by Medscape Medical News, MELD 3.0 was developed to address these gender differences and other determinants of waitlist outcomes. The updated equation added 1.33 points for women, as well as adding other variables, such as albumin, interactions between bilirubin and sodium, and interactions between albumin and creatinine, to increase prediction accuracy. 

To observe the effects of the new system, Kwong and colleagues analyzed OPTN data for patients aged 12 years or older, focusing on the records of more than 20,300 newly registered liver transplant candidates, and about 18,700 transplant recipients, during the 12 months before and 12 months after MELD 3.0 was implemented.

After the switch, 43.7% of newly registered liver transplant candidates were women compared with 40.4% before the switch. At registration, the median age was 55, both before and after the change in policy, and the median MELD score changed from 23 to 22 after implementation.

In addition, 42.1% of transplants occurred among women after MELD 3.0 implementation, as compared with 37.3% before. Overall, deceased donor transplant rates were similar for men and women after MELD 3.0 implementation.

The 90-day waitlist dropout rate — patients who died or became too sick to receive a transplant — decreased from 13.5% to 9.1% among women, which may be partially attributable to MELD 3.0, said Kwong. 

However, waitlist dropout rates also decreased among men, from 9.8% to 7.4%, probably due to improvements in technology, such as machine perfusion, which have increased the number of available livers, she added.

Disparities Continue to Exist 

Some disparities still exist. Although the total median MELD score at transplant decreased from 29 to 27, women still had a higher median score of 29 at transplant, compared with a median score of 27 among men.

“This indicates that there may still be differences in transplant access between the sexes,” Kwong said. “There are still body size differences that can affect the probability of transplant, and this would not be addressed by MELD 3.0.”

Additional transplant disparities exist related to other patient characteristics, such as age, race, and ethnicity. 

Future versions of MELD could potentially consider these factors, said session moderator Aleksander Krag, MD, PhD, MBA, professor of clinical medicine at the University of Southern Denmark and secretary general of the European Association for the Study of the Liver, 2023-2025.

“There are infinite versions of MELD that can be made,” Kwong said. “It’s still early to see how MELD 3.0 will serve the system, but so far, so good.”

In a comment to Medscape Medical News, Tamar Taddei, MD, professor of medicine in digestive diseases at the Yale School of Medicine, who co-moderated the session, noted the importance of using a MELD score that considers sex-based differences.

This study brings MELD 3.0 to its fruition by reducing the disparities experienced by women who were underserved by the previous scoring systems, she said. 

It was lovely to see that MELD 3.0 reduced the disparities with transplants, and also that the waitlist dropout was reduced — for both men and women,” Taddei said. “This change is a no-brainer.”

Kwong, Krag, and Taddei reported no relevant disclosures.

Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.