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An estimated 17,000 Americans are on the waiting list for a liver transplant, and there’s a strong chance that many of them have alcohol-associated liver disease. ALD now edges out hepatitis C as the No. 1 reason for liver transplants in the United States, according to research published Tuesday in JAMA Internal Medicine.

One reason for the shift, researchers said, is that hepatitis C, which used to be the leading cause of liver transplants, has become easier to treat with drugs.

Another could be an increasing openness within the transplant community to a candidate’s history of alcohol and addiction and when a candidate combating these issues can qualify for a liver.

For years, conventional wisdom suggested that people with a heavy drinking past who did not have a period of sobriety under their belts would not be good candidates to receive a new liver. But, of almost 33,000 liver transplant patients since 2002 who were studied, researchers from the University of California-San Francisco found 36.7 percent of them had ALD in 2016, up from 24.2 percent in 2002.

“Across the country, and we show in a prior study, people are changing their minds,” said Dr. Brian P. Lee, the study’s lead author and a UCSF gastroenterology and hepatology fellow. “More and more providers are willing to transplant patients with ALD.”

The debate, roiling for decades, culminated in 1997 when a group of doctors and medical societies and the U.S. surgeon general published a paper that recommended patients with alcoholic liver disease be sober at least six months before they could be considered for transplant.

This “six-month rule” became the gold standard. The idea was that a patient who could stay sober for that long had a lower chance of returning to harmful drinking behavior. There was also concern that the public would stop donating organs if they thought livers would be going to people with alcohol addictions.

“Neither of those attitudes are based on any facts or data,” said Dr. Robert Brown, director of the Center for Liver Disease and Transplantation at Weill Cornell and New York Presbyterian.

The changing attitude plays out at many transplant centers where what once was viewed as a hard-and-fast requirement for six months of sobriety is now more nuanced. Specifically, a team of doctors, psychologists and social workers look at a range of factors, including financial stability and family support, to determine if a patient will relapse after the transplant.

An analysis published in 2010 by researchers from the University of Pittsburgh and a 2011 study in France showed that, in any given year, there was little evidence to suggest six months of abstinence before the transplant decreased the chance of relapse.

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The central point, experts say, does not necessarily come down to a patient’s record of sobriety before the procedure. Foremost is determining that a patient is unlikely to drink again after receiving a new liver — that he or she is “committed to lifelong abstinence,” said Lee.

Five years after transplantation, patients who were abstinent for six months and those who weren’t had about the same survival rates, according to Lee’s research. After 10 years, the patients who didn’t have six months of sobriety before the procedure had slightly worse survival rates. Lee said more research is needed to find out exactly why.

There is nothing magical about six months, according to Dr. Michael Lucey, medical director of the University of Wisconsin liver transplant program. He said it shows a poor understanding of alcohol abuse as a “very complex behavioral disorder.”

“Drinking isn’t a stable phenomenon,” Lucey said. “People with ALD may have long periods of drinking and abstinence.”

Although advocates are glad that policy is changing, it didn’t change swiftly enough to save Chelsea Oesterle.

Oesterle, who was 24 and had battled alcohol addiction since age 16, went to the emergency room in Peoria, Ill., in 2013, already in liver failure. Doctors told her in the first few days that survival depended on a transplant.

When it became clear she wasn’t going to get that transplant, her mother, Terri Oesterle, had her daughter transferred to another hospital, and between both facilities she spent six weeks hospitalized. During that time, she was never put on a transplant list.

The stigma around her daughter’s condition was palpable, her mother said. Doctors and nurses lectured her about quitting drinking.

“They kept telling her she had to go to rehab,” Terri Oesterle said. “She couldn’t even leave the hospital, how on earth was she supposed to go to a rehab program?”

One doctor point-blank asked Terri Oesterle why she thought her daughter deserved a liver over someone else.

“She was dismissed from the get-go,” Terri Oesterle said. “It’s just heart-wrenching because she was such a sensitive soul. She was so scared and hopeful.”

Chelsea Oesterle died in the hospital July 4, 2013.

Alcohol use disorder has often been thought of as a “self-inflicted” disease that results from bad habits or moral failing, Lucey said. That attitude is changing in the medical community, but vestiges remain.

“For some people, it’s not accepting that alcohol use disorder is an illness,” Lucey said.

While support for the changing approach is growing, Lee, the new study’s lead author, said it continues to be a polarizing issue.

“There are still detractors and still strong opposition,” he said. “Our study suggests that is certainly present, because regional differences are disparate.”

That troubles Lee, because it means a patient’s life is dependent on the attitudes of local providers, creating an unequal system. There’s “certainly value” in a national policy on the issue, he said.

The United Network for Organ Sharing (UNOS), the organization that manages the U.S. transplant list, nearly two decades ago wrestled with the idea of formalizing the six-month rule, but never took final action.

As a result, some centers have such a sobriety rule, others don’t. And even when a transplant center gives its approval, insurers often have their own set of requirements about how long a patient must be abstinent before they will cover the transplant.

Dr. David Klassen, chief medical officer for UNOS, agreed that the “rule” is arbitrary and not evidence-based, but said that it should be up to transplant centers to decide who gets listed for an organ.

“From our perspective, dictating medical care doesn’t lead to the best solutions or the best outcomes,” Klassen said. “I think transplant programs and society as a whole are moving in generally the same direction.”

Kaiser Health News is a nonprofit news service covering health issues. It is an editorially independent program of the Kaiser Family Foundation that is not affiliated with Kaiser Permanente.