New federal performance standards for liver transplant centers in the United States may be unintentionally incentivizing doctors to remove potentially viable candidates from organ waiting lists in order to keep up with strict statistical quotas for success, according to new findings published online in the Journal of the American College of Surgeons. The result? More patients who are considered to be “too sick” for liver transplants, and longer wait times for those in need of a new organ, NPR reports.

For the study, researchers at the University of Massachusetts Memorial Medical Center examined trends in so-called delisting at 102 liver transplant centers across the country. The analysis included the outcomes of 90,765 Americans placed on organ waiting lists between 2002 and 2012.

Researchers noted that midway through this study period, in 2007, Centers for Medicare & Medicaid Services (CMS) implemented a new policy for participating Medicare centers that set out to improve standards for one-year survival rates among transplant patients. Under the updated rules, centers that didn’t meet higher performance markers could be flagged for poor performance and possibly risk their participation in Medicare’s transplant program.

Although CMS noted that one-year patient survival for liver transplants increased from 87.7 percent to 90.8 percent as a result of the new guidelines, this new study suggests that the well-intentioned policy may have a dark side. According to researchers, the number of liver transplant patients considered “too ill” or “unsuitable” for the lifesaving surgery post-update has increased by 16 percent. What’s more, patient wait times for an organ have also gone up.

Study authors speculated that the new guidelines might have forced liver transplant centers to be more risk-averse, unintentionally encouraging doctors to drop sicker patients who might have affected their overall survival rate statistics. Others have suggested that liver centers may now be making a more concerted effort to choose the best transplant candidates, rather than treating the most needy patients on their organ donation rosters.

According to the latest CMS statistics, 6,729 liver transplants were performed in the United States in 2014. Another 1,300 people were removed from the waiting list because they were considered “too sick” for the surgery, while 1,821 people in need of a liver transplant died while on the waiting list.

Asked to comment on the study, CMS officials said they were reviewing the evidence of the impacts of the new transplant policy and may consider taking a course of action.