A new study published in the journal Transplantation demonstrates that donor organs labeled “increased risk” are less likely to be used, despite a low risk of disease transmission.

Daniel Kaul, MD, director of the Transplant Infectious Disease Service at Michigan Medicine led an analysis of Organ Procurement and Transplantation Network (OPTN) data showing organs labeled as increased risk are 7% less likely to be used than organs without the label.

Organ donors who recently injected drugs, as well those who were incarcerated or had sex for drugs or money, are among a growing group of people classified as being at “increased risk” of an infectious disease such as hepatitis C or HIV. Despite the very low risk of disease transmission, patients in need are saying no to these organs, which account for 1 in every 5 deceased donor organs today.

“Overall utilization was less despite the extraordinarily low risk of disease transmission,” said Kaul, a professor of internal medicine at the University of Michigan. “The organ may have gone to the next person on the transplant waiting list, but it might not have been used at all.”

utilization rates of the organs varied dramatically by geography. Depending on the donation service area, transplantation of available adult kidneys from increased-risk donors ranged from 20 to 100 percent, the analysis found.

“What that tells us is there may be a different understanding of true risk associated with this label — from one center to another and even within a center, from one organ specialty to another,” Kaul said.

All organs identified as increased risk were less likely to be used with the exception of livers, for which transplant rates were nearly identical. Study authors offered a possible explanation for this: Patients with liver failure may be too sick to say no. By comparison, a patient needing a kidney may continue dialysis and wait for another organ offer.