Donor Source Selection in Hematopoietic Cell Transplantation: Practices and Perceptions Across 50 United States Transplant Centers.

Donor selection for allogeneic hematopoietic cell transplant (alloHCT) is increasingly complex. Transplant centers may benefit from better resources and support to identify and select the best source (related, unrelated, or cord blood). A large-scale quality improvement project gathered data about individual center donor selection practices to better understand center donor search and selection practices, processes, and perspectives to inform the development of resources to support centers. Qualitative data were obtained from interviews of transplant center staff in the United States (US). Eligible centers were US alloHCT transplant centers that performed at least 30 adult alloHCTs in 2022, according to data from the Center for International Blood and Marrow Transplant Research. Interviews (n = 96) were conducted with 156 participants from 50 US centers. Participants included physicians (n = 15), medical directors (n = 30), search/nurse coordinators (n = 84), HLA lab directors/staff (n = 11), and other staff (n = 16), including quality staff and advanced practice providers. Centers represented multiple geographic regions in the US. Interviews revealed diverse decision-making models, ranging from standardized algorithms to individualized approaches. Regardless of the approach to donor selection, centers consistently prioritize degree of HLA-match and donor age, but their relative importance varied by case. Centers reported increasing comfort with mismatched unrelated and haploidentical donors, influenced by clinical trial participation and institutional experience. Urgency, patient population, and logistical constraints often led to adaptation of selection strategies. Experience, intuition, and institutional norms shaped practices alongside evidence. Most centers desired more comprehensive, user-friendly decision-support tools. Despite shared goals, substantial variation in practice was observed. Donor source selection remains a complex, high-stakes process shaped by evolving evidence, operational realities, and human factors. While alloHCT transplant centers share a common goal of optimizing patient outcomes and expanding access, variation in practices reflects both the dynamic nature of the field and the influence of experience, preferences, and emotional weight. As strategies continue to shift, future efforts should focus on providing tailored, evidence-based tools and guidance that respect this diversity while promoting best practices to improve outcomes for all patients.