Study Identifies Reasons to Opt Out of Bone-Marrow Donor Registries

According to a new study by McGowan Institute for Regenerative Medicine affiliated faculty member Mary Amanda Dew, PhD, professor of psychiatry, psychology, epidemiology, and biostatistics at the University of Pittsburgh and also the director of the Clinical Epidemiology Program at the Western Psychiatric Institute and Clinic, and fellow researchers at the University of Pittsburgh School of Medicine, race-specific factors, including religious objections and less trust that donated tissues will be allocated fairly, may help to explain why potential minority donors opt out of bone-marrow donor registries at far higher rates than whites. Additionally, they found that ambivalence about donation was the strongest predictor of opting out, regardless of race.

Published recently in Blood, the journal of the American Society of Hematology, the study is the first to examine factors associated with race and ethnicity that may influence a donor’s decision to commit to hematopoietic stem cell (HSC) donation or opt-out of a registry after being identified as a potential match for an unrelated patient.

HSCs form blood and immune cells and are collected from bone marrow or the bloodstream to re-establish hematopoietic function in patients whose bone marrow or immune system is damaged or defective. As the need for unrelated HSC donors continues to grow to treat cancers and blood-related disorders, such as leukemia and myeloma, the research findings could help to change donor recruitment and retention strategies.

“Minorities searching national donor registries for potential matches today face a two-fold disadvantage,” explained Galen Switzer, PhD, professor of medicine and psychiatry at the University of Pittsburgh and lead author of the study. “Not only is the pool of donors matching their precise blood and tissue types substantially smaller, but there also is a significantly higher rate of attrition from these registries among certain racial and ethnic groups.”

According to data from the National Marrow Donor Program (NMDP), the largest registry of unrelated HSC volunteer donors in the world, approximately 60 percent of potential minority donors who register opt out before donation, compared with 40 percent of whites. Whites have a 79 percent chance of finding a donor match, compared with 50 percent for Asian/Pacific Islanders, 44 percent for Hispanics, and 33 percent for African-Americans.

To try to explain the higher attrition rate among potential minority donors, the researchers interviewed by phone a randomly selected cross-section of five racial and ethnic groups: whites, African-Americans, Hispanics, Asian/Pacific Islanders, and American Indians. They completed interviews with 843 members of a group that continued toward donation after a critical decision point, known as confirmatory typing, in which registry members are identified as a potential match and contacted to undergo blood tests and receive more information about their role as potential donors. The researchers also completed interviews with 224 potential donors who opted out of the registry at this stage of the process.

Based on previous studies, the researchers examined a variety of factors associated with race and attrition from the registry, including demographic, culturally related (such as religious beliefs and mistrust of the medical system), psychosocial (including anxiety and depression), and donation-related (such as concern about health complications).

Dr. Switzer and his colleagues found that four factors were particularly important in terms of their association with minority group membership and increased risk of attrition: As compared to whites, minorities reported more religious objections to donation, less trust that HSCs would be allocated equitably, more concerns about donation, and a greater likelihood of having been discouraged from donating.

In contrast, minorities appeared to be less likely to opt out of the registry if they reported that being a potential donor was an important part of their identity and if others in their social group were aware that they were potential donors.

“Our findings suggest that recruitment messages delivered through mass media, strategies used at donor drives, and the approach to managing individual donors at key points in the donation process can be tailored to overcome potential barriers to donation and to capitalize on factors that might lower the risk of attrition,” said Dr. Switzer.

The study also underscored the prevalence of ambivalence about donation across all groups, including whites, a factor consistently associated with a higher risk of attrition. “Assessing and intervening to reduce ambivalence among all potential donors is an important complementary strategy to race-specific efforts,” added Dr. Switzer. “The ultimate goal in mitigating doubts and worries about donating is to ensure that potential donors are fully educated, confident, and most importantly, comfortable with their decision, no matter what choice they make.”

Illustration: McGowan Institute for Regenerative Medicine.