A new policy across the Atlantic is one that's harvested interest in the U.S. as a possible way to curb the country's drastic shortage of organ donors.

Wales' "presumed consent" organ donation system assumes people want to donate their organs unless they specifically say otherwise – a departure from the opt-in policy employed throughout the U.S. in which people can note such a decision on their driver's license and sign up to be donors through a state registry. Countries like France, Italy and Spain have adopted similar opt-out policies, though Wales is the first in the U.K. to do so and officials say adequate protections are built in for those with concerns about the process.

"The law contains a clear right for relatives and friends of long standing to object to organ donation on the basis that they know the person would not have consented," Welsh Health and Social Services Minister Mark Drakeford tells U.S. News.

The Scottish government also plans to consider an opt-out system, and Welsh officials reportedly hope theirs, which took effect in December, results in a 25 percent boost in transplant rates. But in the U.S. – where a 2013 Health and Human Services report said the gap between organ donors and those in need of a transplant has been growing and results in an average of 100 waiting list deaths per week – proponents of a similar approach haven't gained any traction.

Legislators in states like Colorado, Delaware and New York have pushed for presumed consent; in fact, lawmakers in at least seven states have looked at presumed consent bills between 2011 and 2015. All attempts have failed, however, despite the fact that about half of Americans have said they would support such a system, according to the HHS report.

In New York, former state Assemblyman Richard Brodsky – a Democrat whose daughter has had two kidney transplants – fought for presumed consent during his time in the legislature, but says he was opposed by those concerned it would conflict with certain religious beliefs. Some Orthodox Jews, for example, believe a person isn't dead until his or her heart, not just the brain, stops working.

"Some strictly observant religious people will face some additional difficulties," says Brodsky, now a senior fellow with the public policy organization Demos, "and those can and should be addressed."

Similarly, New Jersey Assemblyman Reed Gusciora, a Democrat whose father suffered from kidney failure, has tried to sponsor a presumed consent bill twice in his state, first in 2012 and again in 2014.

Though the bill gained more support the second time around, he says it still died in committee after pushback from the organ and tissue community. "Every time I try to get the bill posted, there seems to be a flurry of activity and opposition," Gusciora says, adding that opponents feel donation should be voluntary and the process wouldn't be as manageable if everyone donated for "compulsory reasons."

Arnold Schwarzenegger, the former governor of California, was also interested in a presumed consent law when he was in office, thanks in part to the plight of late Apple co-founder Steve Jobs, who received a liver transplant in 2009. But Tom Mone, CEO of OneLegacy, a nonprofit organ and tissue recovery organization which serves the greater Los Angeles area, advised him against it, arguing that California's organ donation rates were already higher than all countries with presumed consent legislation after adjusting for death rates.

The proposal eventually was dropped, and the state started to focus on alternative methods of increasing its number of donors. "Presumed consent sounds like this wonderful, magic wand-waving thing, but it has never been shown to work better than we do," Mone says.

That assertion can be both bolstered and challenged by surface-level data. According to statistics published by the Council of Europe, the U.S. saw a rate of 26.6 deceased organ donors per 1 million people in 2014. That's significantly shy of the 35.7 rate in Spain – a presumed consent country considered the world's leader when it comes to organ donations – but good enough to rank the U.S. among the handful of best performers in the metric. Others include the presumed consent countries of Croatia with a rate of 35.1, Portugal at 27.3 and Belgium at 26.9.

Organ donations and transplants in the U.S. haven't been keeping up with the number of people in need. Organ Procurement and Transplant Network

Past research also has found a 20 to 30 percent increase in organ donation among countries that use presumed consent systems, though Mone and others say such disparities are probably due to other factors. For example, Mone says most countries where the policy has been successful have large Catholic populations, so social and religious influences are at play. And on a purely pragmatic level, Spain's placement of transplant coordinators in hospitals – regardless of the consent policy it uses – is credited as key to helping the country form what many consider the quintessential organ donation model.

Other objections to a presumed consent system include that it would violate patients' autonomy and even infringe on their constitutional rights. Yet some say it isn't the best option simply because it wouldn't be as effective as thought, due largely to the decision-making power and influence held by a donor's family members – an area in which opt-in and opt-out systems aren't really that different. Under the U.S. opt-in system, if a person chooses not to sign up for organ donation and dies, his or her next of kin is consulted to make the decision. And in Wales, as Drakeford notes, family members still hold the trump card if someone does not register their wishes.

A 2012 study by Johns Hopkins University researchers, which included interviews with senior transplant physicians in 13 European countries that used a presumed consent system, found family members can halt the organ donation process even when their considerations aren't legally warranted. Ultimately, the study said, "it seems unlikely that [presumed consent] alone increases donation rates," in part because of the role played by family members.

"The bottom line is, in every system – opt-out or opt-in – we were not able to find anyone that said, 'If the family absolutely, positively said no, we would do the donation anyway,'" says Dr. Dorry Segev, director of the Epidemiology Research Group in Organ Transplantation at the Johns Hopkins School of Medicine and an author of the study. Aside from the obvious sensitivity doctors feel toward families going through a difficult time, they also don't want to risk the "horrible publicity" that could result if members claim their relative's organs were stolen without their approval, he says.

In the U.S., all states have adopted language specifying that families cannot overrule their adult loved one's decision to donate, Mone says. But health care workers still don't want to take organs without the family's consent and don't follow the law in practice, says Arthur Caplan, director of the Division of Medical Ethics at the New York University Langone Medical Center.

"Family plays a huge role in organ donation, no matter what legislatures or lawyers think," Caplan says, noting that's why people should clearly express their wishes to their loved ones.

But Caplan says he still thinks a presumed consent system could help close the donation gap to a small degree, and notes that public opinion polls have shown most Americans actually want to be organ donors. According to the Health and Human Services study, around 95 percent of Americans supported organ donation in 2012 and about 60 percent of those who hadn't signed up to be an organ donor were willing to do so through a state registry. In theory, a presumed consent policy would broaden the net to include those OK with donating who simply haven't listed themselves as donors yet.

Caplan says a presumed consent policy also changes the way doctors talk to families about organ donation, shifting the conversation from, "'This is a terrible time to have to ask this, but have you thought about organ donation?'" to "'Most people want to do this – is there any reason your daughter wouldn't want to?'" Yet a branding change would be necessary in the U.S. for such a system to be successful, he says, suggesting it be called "default to donation" because "Americans get very upset when you presume something about their consent."

Mone agrees: "If you're not giving up your guns, you're not giving up your kidney," he says.

Since states can make their own laws regarding organ donation, a presumed consent system would probably have to be adopted on a state-by-state basis, further cementing the notion that it would only lead to minor, incremental gains. The only federal law states have to follow is that people can't buy and sell organs, Caplan says.

"I'm not looking for a huge increase in organs because people, again, still find this a very tough area to deal with [when there are] boots on the ground, as opposed to what the laws are," Caplan says. "But it will help a bit. It just makes it emotionally and psychologically easier to approach families."

But Segev says instead of presumed consent, in which he contends assumptions may have to be made about people's wishes, he would rather see a stronger opt-in system that better informs people about the donation process. This could also be preferable for organ recipients who want to be certain their donors made the choice to give away their organs themselves.

Chad Southward, policy manager at the United Network for Organ Sharing – a nonprofit federally contracted to manage the organ transplant system in the U.S. – says it's better to have the donors and their families involved in the process, which an opt-in system facilitates. Although UNOS has no official stance on the adoption of a particular organ donation policy, Southward, who has had two double lung transplants, speaks from the perspective of an organ recipient.

"Donation and transplantation can't happen without the grief of another family and, in my recipient opinion, it is positive to have those families – or those individuals that have spoken their wishes to be organ donors – to have them as part of the process," he says.

While experts disagree about which system would be most beneficial, they still concur that without additional measures, neither an opt-in nor an opt-out system can solve the donor shortage problem on its own. "No matter what we do, whether we have presumed consent, default to donation or even [if we] paid people money to try to incentivize them to sell their organs, there just aren't that many people who die in circumstances where they can be organ donors," Caplan says.

When people die in a hospital's intensive care unit while hooked up to machines, for example, Caplan says their organs are usually viable. But when someone dies in the emergency room, his or her organs are only viable for a short time, meaning many possible donors' organs are never used.

If these ER patients are put on machines before they die, or if their organs are removed very quickly, "we'd have a bigger pond with more fish in it to look for," Caplan says.

In California, the state has implemented a policy through which adolescents learn about the organ donation process in high school so they are well-informed about their options before making a decision at the Department of Motor Vehicles. Mone also has recommended giving tax breaks to living kidney donors.

And in a step that would resemble a facet of Spain's top-notch organ donation system, Segev says Congress should pass a bill requiring every hospital in the U.S. to have a champion for organ donation – a health care provider who understands organ policies and can better inform patients and their loved ones about donation options.