There are 93,000 people in the United States waiting for a kidney transplant, and kidney disease kills about 5,000 U.S. residents on the kidney waiting list annually—yet a study published last week in JAMA Internal Medicine finds the United States throws away at least 3,500 donated kidneys every year.

Here are 5 key tactics to attract and retain transplant patients

Study details

For the study, researchers looked at deceased donor kidney donations that took place between 2004 and 2014 in the United States and France and analyzed how those kidneys were used. The researchers did not look at survivability outcomes for transplant recipients to determine overall success rates for each country.

The researchers found that 156,089 kidneys were donated from deceased individuals in the United States from 2004 to 2014, and 27,987—or 17.9%—of the kidneys were discarded. By comparison, 29,984 deceased donor kidneys were donated in France over the study period, and 2,732—or 9.1%—of those kidneys were discarded.

The researchers said doctors in France were more willing to use older kidneys and kidneys from donors who had other illnesses, such as diabetes or hypertension, than U.S. doctors. "We found that the age and [Kidney Donor Risk Index (KDRI)] of U.S. deceased donor kidneys remained stable from 2004 to 2014 … whereas the French transplant system responded to the organ shortage by accepting lower-quality kidneys, especially those from older donors," the researchers wrote.

For instance, the researchers found that the mean age of kidneys transplanted in the United States from 2004 to 2014 was 36.51 years, compared with 50.91 years in France.

The researchers concluded that, had the United States adopted France's model of kidney acceptance, an additional 17,435 of the donated kidneys in the United States would have been transplanted, which could have generated an extra 132,445 years of life from 2004 to 2014.

US hospitals take a risk adverse approach to kidney transplants, experts say

The researchers wrote that one of the main reasons the United States does not accept lower-quality kidneys is because there is "intense regulatory scrutiny of U.S. transplant programs, which may lose credentials if their one-year death and graft failure outcomes exceed predicted outcomes." As a result, U.S. transplant centers tend to be more risk-averse.

In a commentary accompanying the study, Brigham and Women's Hospital's Ryoichi Maenosono and Stefan Tullius, who were not involved in the study, wrote, "It is recognized that the overly stringent and restrictive process of monitoring transplant programs in the United States has resulted in many transplant programs taking a risk averse approach." They added, "Hospital administrators and patients alike are attracted by superficial five-star ranking approaches that are easy to read but not necessarily reflective of the approach of individual programs aiming to provide their patients on waiting lists with the best opportunities."

For instance, Maenosono and Tullius wrote that, unlike the United States, Europe uses an "old-for-old" approach to organ donations, meaning older kidneys that otherwise would have been rejected are sometimes used for older patients. "[W]e should focus more on the needs of the potential recipients and less on the donor kidneys," they wrote.

A 2013 study found that Europe had better survivability outcomes for kidney transplants, with five- and 10-year graft survival rates of about 77%, when compared with the United States, which had five- and 10-year graft survival rates of about 56%.

Kevin Longino, CEO of the National Kidney Foundation, said pressure to accept higher-quality kidneys in the United States comes from hospital administrators looking to save money. "Kidneys that have higher KDPIs take longer to 'wake up,'" Longino explained, adding, "Administrators don't want to take the risk because they don't get reimbursed for the number of days that [transplant patients are] hospitalized."

Transplant centers also have to decide whether to refuse a kidney within 60 minutes of its donation, before it is taken to another transplant center. Most transplant centers use biopsies to make that decision but, according to Sumit Mohan, an associate professor of medicine and epidemiology at Columbia University, those biopsies often are rushed and can be misinterpreted.

Mohan said a more careful use of biopsies could make a big difference in the number of donated kidneys transplanted in the United States (Christensen, CNN, 8/26; Rodriguez, USA Today, 8/30; Parry, Medscape, 8/27; Aubert, JAMA Internal Medicine, 8/26).