Here's how a 2003 BBC article starts:
The system for allocating most liver transplants on the NHS is causing younger patients to wait longer for surgery, figures show.
There is a shortage of liver donors, so a computer algorithm decides who to prioritise on the waiting list.
Younger people are currently waiting 156 days longer on average for a transplant than patients over 60.
But NHS Blood and Transplant (NHS BT) says difficult decisions have to be made and the system is saving lives.
The AI Snake Oil blog discusses the algorithm (and other algorithms) in depth:
In November 2023, the Financial Times published a bombshell investigation about bias in the algorithm. It centers on a 31 year old patient, Sarah Meredith, with multiple genetic conditions including cystic fibrosis. It describes her accidental discovery that the Transplant Benefit Score algorithm even existed and would decide her fate; her struggle to understand how it worked; her liver doctors’ lack of even basic knowledge about the algorithm; and her realization that there was no physician override to the TBS score and no appeals process.
When she reached out to the National Health Service to ask for explanations, Meredith was repeatedly told she wouldn’t understand. It seems that the paternalism of health systems combined with the myth of the inscrutability of algorithms is a particularly toxic mix.
Meredith eventually landed on a web app that calculates the TBS, built by Professor Ewen Harrison and his team. He is a surgeon and data scientist who has studied the TBS, and is a co-author of a study of some of the failures of the algorithm. It is through this app that Meredith realized how biased the algorithm is. It also shows why the inscrutability of algorithmic decision making is a myth: even without understanding the internals, it is easy to understand the behavior of the system, especially given that a particular patient only cares about how the system behaves in one specific instance.
But this isn’t just one patient’s experience. From the Financial Times piece:
“If you’re below 45 years, no matter how ill, it is impossible for you to score high enough to be given priority scores on the list,” said Palak Trivedi, a consultant hepatologist at the University of Birmingham, which has one of the country’s largest liver transplant centres.Finally, a 2024 study in The Lancet has confirmed that the algorithm has a severe bias against younger patients.