A rapid review of motives and barriers for living substance of human origin donation and an extended typology.

Our objective is to review motives and barriers for non-reproductive, living substance of human origin (SoHO) donation, and to extend existing typologies beyond blood. The expansion of SoHO collection is currently unmatched by increased living donors. Thus, there is a critical need to understand how to effectively recruit and retain donors to ensure a sustainable supply of SoHO. We undertook a rapid review and narrative synthesis of published, peer-reviewed literature reporting on motives and/or barriers for living SoHO donation (whole-blood, blood products [2009-2023], bone marrow/stem cells, cord blood, organ, human breast milk, intestinal microbiota [2000-2023]). Results were interpreted through directed qualitative content analysis using an extended typology of motives/barriers largely drawn from blood donation research, and subsequently refined based on results to be inclusive of other SoHO. 234 articles with 237 studies met review criteria. Most were quantitative (74.3%), conducted in Western countries (63.8%), focused on blood donation (64.2%), reported motives and barriers (51.9%) and did not examine differences by donor characteristics or history (74%). We present a revised typology inclusive of motives/barriers for donation of substances beyond blood. This shows while broader motives and barriers are shared across substances donated, there are critical differences at the subcategory level that may account for heterogeneity in results of prior interventions. The nuances in how broad categories of motives and barriers manifest across different SoHO are critical for blood collection agencies to consider as they attempt to expand collection of products beyond whole-blood, plasma, and platelets. WHAT IS KNOWN ABOUT THE TOPIC?: Blood collection agencies (BCAs) continue to expand SoHO product collection beyond whole-blood, plasma, and platelets. The demand for SoHO is currently unmatched by increased living donors. The need to understand how to recruit new and retain existing living donors to ensure a sustainable supply of SoHO remains critical. However, there is no available synthesis of the factors, such as motives/facilitators and barriers/deterrents, to inform our understanding. WHAT IS NEW?: Comprehensively reviewed evidence for motives and barriers of willing/actual donors and nondonors across all types of non-reproductive living SoHO donation. Explored variations in motives and barriers based on substance, donor history and demographic differences (gender, age, ethnicity or culture). Extended typology of motives and barriers inclusive of all non-reproductive living SoHO, beyond solely whole-blood and blood products. Identified that while there are commonalities in the overarching motive and barrier categories across substances (e.g., prosocial motivation, low self-efficacy), within these broader constructs there are differences at the subcategory level (e.g., low-self efficacy was about eligibility, lifestyle barriers, or lack/loss of financial or material resources depending on the substance donated) that are crucial for development of future interventions and for BCAs to consider as they expand SoHO product collection. Highlighted the continued focus on motives and barriers for whole-blood and blood product donation to the exclusion of other, particularly newer, SoHO; lack of qualitative work for newer SoHO; and lack of consideration of differences based on donor characteristics (especially ethnicity/culture) and donor history, which limits our understanding. WHAT ARE THE KEY QUESTIONS FOR FUTURE WORK ON THE TOPIC?: What are the motives and barriers (in both qualitative and quantitative studies) for donation of newer SoHO such as stem cells, cord blood, human milk, and intestinal microbiota? Are there differences in motives and barriers within and across SoHO that are informed by individual and contextual-level factors? How can we develop interventions that respond to the nuances of motives and barriers present across different forms of SoHO that are effective in encouraging new and maintaining continuing donors?