Exception scores

MELD scores and PELD scores

For most liver transplant candidates, medical urgency is determined by an evidence-based formula, either MELD for candidates age 12 and older or PELD for those younger than 12. Each formula uses objective medical data to assess how likely a person is to survive in the short term without a liver transplant.

What is an exception score?

Some transplant candidates have a medical condition, such as cancer or rare forms of chronic liver disease, where MELD or PELD will not accurately predict their short-term transplant need. If so, they may qualify for an exception score — a separately assigned score to be used instead of their calculated MELD or PELD in matching the person for available organ offers.

The goal of exception scores is to make access to transplant more equitable among patients with similar levels of medical urgency.

Standard exception scores

Some medical conditions (for example, certain forms of liver cancer) are common enough that the liver transplant candidate can get a standard exception score – the same assigned score for any person with that condition. To qualify for a standard exception, the liver program needs to document that the person’s medical condition meets criteria outlined in OPTN policy.

For most medical conditions involving a standard exception, the candidate will get a score that is indexed at a level of urgency similar to people who don’t have exceptions. This index is based on a calculated score for each hospital where there could be a liver donor.

Median MELD at Transplant (MMaT) scores

For MELD patients (age 12 or older) with an exception score, the index that is used is based on the median (statistical midpoint) of MELD scores for people who recently have had liver transplants within an area surrounding the hospital where the individual liver donor is. This value is called the Median MELD at Transplant (MMaT). 

The MMaT will be unique to each donor hospital, based on the scores of recently transplanted recipients in that area. 

For example, at one donor hospital, half of the liver recipients transplanted nearby had a MELD score higher than 31, and half had a MELD score lower than 31. The midpoint of those scores – the MMaT – will be 31 for that donor hospital. The median differs from one hospital to the next.

At the time of a liver offer, most candidates with a standard MELD exception will have a score, for that individual offer, of three points less than the MMaT of that specific donor hospital. If the donor hospital has a median of 31, these exception candidates all will have a score of 28. For a different liver donor at a different donor hospital with a median of 29, the exception candidates will have a score of 26.

This approach is designed to ensure that exception candidates are compared the same way with each other, and that they have appropriate transplant priority for that liver offer alongside other non-exception candidates who have a score based on the MELD calculation.

Median PELD at Transplant (MPaT) scores

Liver candidates younger than age 12 may qualify for a standard exception that is based on the statistical median (midpoint) of transplants performed nationwide for children with a PELD score. This median score is known as the Median PELD at Transplant (MPaT). Unlike the median MELD, the MPaT is calculated based on all transplants done nationwide for children with a PELD score. Thus the MPaT is the same value for all candidates nationwide with a PELD exception, and it does not vary by the donor hospital.

Most transplant candidates with a standard PELD exception will have a score equal to the national median (MPaT) when being considered for organ offers. Again, this is meant to balance the transplant priority of PELD exception candidates in relation to one another and to non-exception candidates who have a PELD based their calculated score.

Customized exceptions and review of exception requests

Some candidates may be sicker than the standard exception score would indicate. In these cases, the person may have a condition that does not meet criteria for a standard exception score. In that instance, a patient’s transplant hospital (the transplant team) makes customized exception score requests to a national review board of independent medical experts made up of liver transplant physicians and surgeons.

In many cases, the custom score requested will again be indexed to the median MELD or PELD score at transplant (MMaT) or (MPaT), not a set score. This is done to balance the priority of a person with a custom exception score along with other transplant candidates, whether they have an exception score or not.

Requests examined by the review board contain no patient or hospital identifiers so that the review is completely unbiased and based only on medical information. The review board is tasked with deciding whether the requested score is reasonable based on the patient’s current medical condition and the likelihood that the recipient will do well once transplanted.

The National Liver Review Board

The National Liver Review Board (NLRB) consists of volunteer medical experts who practice transplantation throughout the United States. It considers all exception requests on an anonymous basis, with no information about the candidate’s identity or the hospital making the request. The board makes its decision based solely on the medical facts supplied by the transplant hospital, aided by their own medical judgment and guidance from the OPTN. The review board may grant or deny the exception score requested.

If the initial request is denied, the transplant hospital listing the candidate can choose to pursue a series of up to three appeals. Through the appeal process, the patient’s transplant team has the opportunity to provide additional detail to clarify questions that may arise in earlier review. In each instance, the reviews are conducted based on the medical facts presented, the medical expertise of the reviewers and applicable OPTN guidance.

How the review board works

The National Liver Review Board (NLRB) was implemented in 2019. It replaced a system of 11 separate review boards, one for each OPTN Region.

The NLRB provides consistency by using national guidance to assess exception scoring requests. It consists of three specialty boards (adult hepatocellular carcinoma diagnosis (HCC); Pediatrics; and Adult Other Diagnoses). This ensures that needed expertise is present on each board and improves consistent decision-making. Each review board consists of members from across the country.

A number of medical conditions may qualify the candidate for a standard exception. This is a fixed value relative to the median MELD or PELD score for recipients recently transplanted in the area surrounding their transplant program, surrounding area at the time they received their transplant.

In other instances, the candidate has a condition that does not meet requirements for a standard exception. If so, the candidate’s transplant team provides medical information to the NLRB and requests a custom score they believe is appropriate.

The NLRB uses established guidance and medical judgment in deciding whether to grant or deny the hospital’s exception point request.

NLRB membership and process

Every liver transplant hospital can be represented on the NLRB. Each liver transplant hospital may appoint a representative and alternate to each of the specialty boards. Review board members are trained before they begin service on topics including exception policy, operational guidelines, and guidance for evaluating common types of exceptions.

For each exception request, the five assigned anonymous experts log into a secure web-based application, where the patient’s liver transplant hospital has posted both clinical data about the patient (identifiers removed) and narrative information in a free text field for reviewers to examine. The transplant hospital also requests the exception score it thinks appropriate.

NLRB members review each application to ensure that the score requested meets the clinical situation. Reviewers consider only medical information. They do not get information identifying the patient, the hospital, or the part of the country where the patient is waitlisted.

The review board members approve or decline the exception score requested. Reviewers vote on the site, and once two “No” votes or four “Yes” votes are received, voting closes. A request must achieve four of five affirmative votes in order to be approved. If an NLRB member votes to deny a request, he/she must provide an explanation.

Appeal process

If the NLRB declines a requested exception score, the transplant hospital may appeal the decision for further consideration. The first appeal goes back to the same panel of five reviewers that denied the request the first time. This gives the hospital a chance to provide more information and respond to any comments that the review panel provided.

If the initial review group declines the first appeal, the hospital can appeal to a different group of reviewers, called the Appeals Review Team (ART), which has nine members who meet weekly by conference call. The hospital requesting this second appeal has the opportunity to join the call, explain any nuances in the case, and have a two-way discussion with reviewers.

If the ART appeal is not favorable, the hospital may appeal to the OPTN Liver and Intestinal Transplantation Committee.