Role of Race/Ethnicity in Donor Decisions about Unrelated Hematopoietic Progenitor Cell Donation: Exploring Reasons for Higher Attrition among Racial/Ethnic Minorities

Racial/ethnic disparities in availability of volunteer unrelated donors for allogeneic transplantation

ABSTRACT

Despite the global unrelated donor (URD) registry size, the degree to which URD availability is a transplant barrier is not established. We evaluated the availability of 3,843 URDs requested for 455 diverse adult patients (predominantly with acute leukemia). URDs for non-Europeans were more likely to be domestic and had markedly lower Donor Readiness scores. Of URDs requested for confirmatory HLA-typing (CT) alone (ie, without simultaneous workup), 1,894 of 3,529 (54%) were available. Availability of domestic URDs was 45%. Donor Readiness score was highly predictive of CT availability. More non-European patients (n = 120) than Europeans (n = 335) had >10 URDs requested and <5 available. Of workup requests (after CT or CT-workup), <70% (604/889 [68%]) were available. More non-Europeans had <2 URDs available. URD availability for CT was markedly worse for non-Europeans, with availabilities for African, non-Black Hispanic, and Asian patients being 150/458 (33%), 120/258 (47%), and 119/270 (44%), respectively, with further decrements in URD workup availability. Our data suggest the functional size of the URD pool is much smaller than appreciated, mandating major operational changes for transplant centers and donor registries. Likelihood of donor availability should have a high priority in donor selection. Considering patient ancestry and URD Donor Readiness scores, centers should pursue, and registries permit, simultaneous pursuit of many URDs and abandon futile searches. Patients should be informed about their likelihood of donor availability and alternative options. Finally, although registries should address high URD attrition and speed procurement, use of all HLA-disparate graft types is needed to facilitate timely transplant for all.

Factors Associated with Opting Out of an Unrelated Hematopoietic Stem Cell Donor Registry: Differences and Similarities across Five Key Groups of Young Race/Ethnically Diverse Potential Donors in the United States

Young adults from underserved racial/ethnic groups are critically needed as unrelated hematopoietic stem cell (HSC) donors, yet they are more likely than other groups to opt out of donation after having matched a patient. Understanding which factors are most strongly associated with opting out among young underserved racial/ ethnic registered donors compared with their White counterparts will provide the basis for specific interventions to improve donor retention. We sought to determine the key, modifiable psychosocial, registry-related, and donation-related characteristics that are uniquely associated with opting out across 5 key racial/ethnic groups of young HSC donor registry members who had been contacted as a potential match for a patient. This study examines data from a large cross-sectional survey of young (age 18 to 30) registry members shortly after they preliminarily matched a patient (CT-stage) and continued toward or opted out of donation (CT-C and CT-NI), stratified by racial/ethnic group and sex. We assessed psychosocial, registry-related, and donation-related characteristics for all participants. We used chi-squared and F tests to assess differences between racial/ethnic groups. A separate logistic regression analysis for each racial/ethnic group was conducted to quantify adjusted associations between each variable and opting out. Then, we compared these associations across the racial/ethnic groups by evaluating the interaction effect between each variable and racial/ethnic group, with the same outcome (CT-C versus CT-NI) in question. Nine hundred thirty-five participants were surveyed, including 284 White, 165 Hispanic, 191 Black, 192 Asian/Pacific Islander, and 103 Multiracial/multiethnic participants. There were significant differences across racial/ethnic groups in values/goals, religious objections to donation, HSC-related medical mistrust, and parental involvement in donation decisions. Adjusted logistic regression subgroup analyses indicated that ambivalence was strongly associated with opting out across all racial/ethnic groups. Greater focus on intrinsic life goals (e.g., raising a family, becoming a community leader, influencing social values) was associated with opting out in the Multiracial/multiethnic, Hispanic, and Asian/Pacific Islander groups. Healthcare mistrust and insufficient registry contact was a significant factor for Hispanic participants. Protective factors against opting out included remembering joining the registry (Black participants), and parental support for donation decision (Asian/Pacific Islander participants). The performance of each logistic regression model was strong, with area-under-the curve ≥.88, CT-stage outcome classification accuracy ≥89%, and good fit between expected and observed opt-out probabilities. In the analysis across different racial/ethnic groups, the only significant interaction was race/ethnicity by whether more contact with the registry would have changed the decision at CT-stage; this variable was significant only for the Hispanic group. In the within-group analysis for Hispanic participants, the "more registry contact" variable was strongly associated with opting out (odds ratio 5.8, P = .03). Consistent with a growing body of HSC donor research, ambivalence was a key factor associated with opting-out for all racial/ethnic groups. Other key variables were differentially associated with opting-out depending on racial/ethnic group. Our study highlights key variables that registries should focus on as they develop targeted and tailored strategies to enhance commitment and reduce attrition of potential donors.

Providing hematopoietic stem cell products from unrelated donors to the world: DKMS donor centers and DKMS Registry

Allogeneic hematopoietic stem cell (HSC) transplantation is a curative therapy for many severe blood diseases. As many patients have no suitable family donor, large unrelated donor registries and donor centers have been established in many countries, along with an international system for the provision of unrelated donor HSC products. As an essential part of this system, DKMS operates donor centers in 7 countries with a total of 12.2 million donors and over 114,000 donations so far, and a multinational donor registry. In 2022, DKMS donors contributed 57.5% of all cross-border donations worldwide. In this review, we describe the international system for the provision of unrelated donor HSC products as well as tasks and responsibilities of donor registries and donor centers. We also discuss relevant aspects of DKMS donor centers, namely donor file composition, matching and donation probabilities and actual donations, and the unique multinational approach of the DKMS Registry.

Utilization and outcome disparities in allogeneic hematopoietic stem cell transplant in the United States

Allogeneic hematopoietic stem cell transplant (allo-HSCT) is increasingly being used in the United States (US) and across the world as a curative therapeutic option for patients with certain high-risk hematologic malignancies and non-malignant diseases. However, racial and ethnic disparities in utilization of the procedure and in outcome following transplant remain major problems. Racial and ethnic minority patients are consistently under-represented in the proportion of patients who undergo allo-HSCT in the US. The transplant outcomes in these patients are also inferior. The interrelated driving forces responsible for the differences in the utilization and transplant outcome of the medical intervention are socioeconomic status, complexity of the procedure, geographical barriers, and the results of differences in the genetics and comorbidities across different races. Bridging the disparity gaps is important not only to provide equity and inclusion in the utilization of this potentially life-saving procedure but also in ensuring that minority groups are well represented for research studies about allo-HSCT. This is required to determine interventions that may be more efficacious in particular racial and ethnic groups. Various strategies at the Federal, State, and Program levels have been designed to bridge the disparity gaps with varying successes. In this review paper, we will examine the disparities and discuss the strategies currently available to address the utilization and outcome gaps between patients of different races in the US.

Analysis of disparities in time to allogeneic transplantation in adults with acute myelogenous leukemia

Although alternative donors extend transplant access, whether recipient ancestry affects the time to allogeneic transplant is not established. We analyzed the likelihood of clinically significant delays to allograft by patient ancestry in 313 adult patients with acute myelogenous leukemia (AML) who underwent transplantation. Non-European ancestry patients (n = 99) were more likely than Europeans (n = 214) to receive HLA-mismatched donor allografts (45% vs 24%). Overall, the median time from transplant indication to allograft was 127 days (range, 57-1683). In multivariable analysis, non-Europeans had an increased risk of prolonged indication to transplant time >180 days owing to significant delays in indication to consult >90 days and consult to transplant >120 days. Compared with recipients of HLA-matched unrelated donors (URDs), HLA-mismatched adult donor recipients were at an increased risk of delayed indication to transplant, whereas HLA-identical sibling and cord blood recipients were at a lower risk. Subanalysis showed more indication to transplant delays >180 days in non-European (44%) vs European (19%) 8/8 URD recipients. Finally, the pandemic further exacerbated delays for non-Europeans. In summary, although non-European patients with AML are less likely to receive 8/8 URDs as expected, if they do, their transplants are delayed. HLA-identical siblings and cord blood facilitate the fastest transplants regardless of patient ancestry, whereas other adult donor transplants are delayed. Strategies to mitigate referral barriers, hasten donor evaluation, and use all alternative donor sources are critical to ensure timely transplantation for patients with AML.

Factors Associated with Opting Out of Donation among Registered Young Unrelated Hematopoietic Stem Cell Donors

Young adults enrolled in hematopoietic stem cell (HSC) donation registries, including the Be The Match registry in the United States, often opt out of the registry when a potential recipient is identified. This results in a limited supply from the most desirable allogeneic source of HSCs used in transplantation to treat serious health conditions. The differences in demographic, psychosocial, registry-related, and donation-related characteristics between those who continue to donation and those who opt out may elucidate the modifiable risk factors for attrition, but these characteristics have not been extensively studied in young donors up to age 30 years. Our goal was to study demographic, psychosocial, registry-related, and donation-related characteristics in a group of young HSC donor registry members who had recently been contacted about a potential recipient, to determine the key characteristics that differ between those who continued toward donation and those who opted out and to examine the extent of these differences. We conducted a cross-sectional survey in a random sample of young (age 18 to 30 years) current and former registry members, stratified by race/ethnicity and sex. Demographic, psychosocial (eg, life goals, HSC allocation mistrust), registry-related (eg context and motive for joining the registry), and donation-related (eg, ambivalence, religious objections to donation, knowledge about donation) characteristics were assessed. Chi-square and 2-sample t tests were used to examine differences between those who continued (CT-C group) and those who opted out (CT-NI group). Hierarchical logistic regression was used to estimate adjusted covariate effects on the odds of opting out. A total of 935 participants were surveyed. Donation-related knowledge was higher in the CT-C group than in the CT-NI group. HSC allocation mistrust, religious objections, and concerns about donation were higher in the CT-NI group. After adjusting for covariates in a logistic regression model, we found that having more intrinsic life goals, having more ambivalence, and talking with registry staff only once/twice were significantly associated with opting out of the registry. Ambivalence had the strongest association with opting out. In contrast, remembering joining the registry, believing that parents would support donation, and having medical concerns were significantly associated with continuing toward donation. This effect of medical concerns on donation was discovered only after adjusting for the related but distinct ambivalence variable, with the remaining effect of medical concerns relating to engagement with the donation process and information-seeking. The model had strong discriminative ability (area under the receiver operating characteristic curve = .92) and classification accuracy (86.6%). Our data indicate that among young adult members of a national HSC donor registry, ambivalence and limited contact with registry staff were more strongly associated with opting out of donation. Medical concerns were associated with continuing toward donation. Further studies are needed to confirm a causal link between medical concerns and continuing to donation among young donors. Our study suggests that these concerns might not be directly related to attrition, whereas other factors (eg, ambivalence, low donation-related knowledge) are associated with attrition and thus should be targeted for attrition reduction strategies.

Why We Swab: A library of stories in stem cell donation

BACKGROUND

Stories are powerful in their ability to disseminate information in a meaningful way. We hypothesized that a stem cell donation story library optimized for social media could support the education and recruitment of committed unrelated hematopoietic stem cell donors from needed demographic groups.

STUDY DESIGN AND METHODS

We developed Why We Swab, a library of stories on stem cell donation (facebook.com/WhyWeSwab; instagram.com/WhyWeSwab; twitter.com/WhyWeSwab), and evaluated its impact across social and traditional media as well as on eligible potential donors' knowledge and attitudes towards donation.

RESULTS

As of December 2021, the library included 28 story arcs featuring 45 storytellers from diverse ancestral backgrounds, including 8 donor-recipient stories. Overall, the stories reached >92,000 people across social media. Notably, stories were republished by 18 print/ broadcast media outlets in Canada and by major medical organizations. A series of stories shown to 33 eligible potential donors improved mean total scores on a donation knowledge test (64% to 85%, p < 0.001), reduced mean ambivalence scale scores (3.85 to 2.70, p < 0.001), and improved participants' willingness to register as donors (45% to 73%, p < 0.005). Data are also shown demonstrating that stakeholders valued the library and that its deployment was associated with improved donor recruitment outcomes in Canada.

CONCLUSION

Why We Swab is accessible and relevant to a wide audience, including stem cell donor registries and recruitment organizations seeking to improve their recruitment efforts as well as to blood and organ & tissue donation organizations who can adapt the Why We Swab model to their audiences.

Development and evaluation of checklists to support the recruitment of committed hematopoietic stem cell donors

BACKGROUND

Checklists are memory recall tools used across healthcare to improve outcomes. Here, we describe the development and evaluation of checklists to support recruitment of committed allogeneic hematopoietic stem cell donors.

STUDY DESIGN AND METHODS

Checklists were developed with the following objectives: (1) improve best-practice adherence; (2) reduce errors; and (3) support standardization at stem cell drives. Topics included: recruiting needed donors; securing informed consent; maintaining good-documentation practices; and supervising registration and tissue sample collection. Checklists were iteratively revised with input from stakeholders. We evaluated the checklists by examining recruitment outcomes and errors (i.e., preventing registrants from being listed as donors) pre- (11/2011-8/2016) and post- (9/2016-11/2019) implementation by the Canadian donor recruitment organization Stem Cell Club. Quantitative and qualitative methods were employed to analyze recruiters' perspectives on the checklists.

RESULTS

The checklists supported recruitment of donors from needed demographic groups as Stem Cell Club expanded its recruitment effort from 4118 registrants (60% male, 58% non-European) pre-implementation to 10,621 (52% male, 56% non-European) post-implementation. Checklist implementation was associated with a marked reduction in errors (from 13.2% to 1.9%) and a three-fold increase in the match rate of recruited donors (from 0.024% to 0.075%). Qualitative and quantitative analysis of recruiter feedback supported that the checklists' objectives were realized from the recruiter perspective.

DISCUSSION

We developed checklists to support donor recruitment and showed that their implementation was valued by recruiters and associated with both reduced errors and improved donor recruitment outcomes. The checklists are relevant to donor recruitment organizations worldwide.

A review of whole-blood donors' willingness, motives, barriers and interventions related to donating another substance of human origin

Diversification of blood collection agencies' (BCAs) core business requires donors to donate substances of human origin (SoHO) beyond whole-blood. Whole-blood donors are assumed to be willing to convert to donate other SoHO as well as whole-blood. However, no reviews consider the evidence on conversion (i.e., willingness/intention, behaviour, retention, attrition). This rapid review provides a narrative synthesis of whole-blood donors' conversion to another SoHO, characteristics contributing to conversion, motives and deterrents, and interventions encouraging conversion. Sixty-five studies were reviewed. Most were cross-sectional and examined whole-blood donor conversion to organ (willingness/pledge for deceased donation), plasma or stem cell donation. Most examined conversion rather than characteristics contributing to conversion, motives, deterrents or interventions. Whole-blood donors appear willing to donate another SoHO, yet conversion rates are unclear. Besides self-efficacy, there is little consistency in reported characteristics of donors converting, and few theories applied to understand characteristics encouraging conversion. Intrinsic (altruism, self-esteem, curiosity) and extrinsic (perceived need, service experience, direct requests) motives and barriers (lifestyle, fearing reduced health) appear important and require further research. Interventions encouraging conversion need replication and may include in-person, in-centre approaches, raising awareness of the functional benefits of other SoHO (high need, usefulness), and developing promotional materials that pique donors' curiosity, invite questions, and encourage donor-initiated conversations about conversion. Centralising BCAs as a single business or partnering with other organisations appears mutually beneficial to encourage conversion and sustainable panels/resources. Research is needed to understand the impact of encouraging conversion on donors and organisations, and identify optimal management strategies for multi-SoHO donors.

Development and evaluation of a community of practice to improve stem cell donor recruitment in Canada

Background and Objectives Communities of practice (CoPs) represent effective models to achieve quality outcomes in health care. We report the development and evaluation of a CoP to improve stem cell donor recruitment in Canada. Materials and Methods In September 2017, we invited national stakeholders in stem cell donor recruitment to participate in a Facebook group and regular e-meetings. E-meetings involved speakers and roundtable discussion on topics related to donor recruitment. The Facebook group facilitated sharing of resources. We evaluated stakeholder perspective of the CoP and the impact on recruitment outcomes. Results As of December 2020, the CoP included 382 members who published 243 posts to the Facebook group about patient/donor stories (40%), resources (27%), updates/questions (21%) and recruitment outcomes (12%). In January 2020, we surveyed 44 CoP participants; the majority felt that the Facebook group (86%) and e-meetings (59%) supported the community, and that the CoP fostered collaboration (82%), improved their donor recruitment knowledge (75%) and practice (77%) and improved their ability to recruit needed donors (64%). The launch of the CoP correlated with improved donor recruitment outcomes. In 2016-2017, CoP participants recruited 2918 registrants (46% male; 55.9% non-Caucasian) compared to 4531 registrants in 2018-2019 (52.9% male; 62.7% non-Caucasian). Members of the CoP developed innovative resources to support recruitment efforts and led national campaigns securing coverage in major media outlets. Conclusion We describe the first CoP in stem cell donor recruitment to be formally evaluated. The CoP model may be adopted by donor recruitment organisations, registries and blood banks worldwide to improve recruitment outcomes. HIGHLIGHTS: • A community of practice (CoP) in stem cell donor recruitment was valued by participants and supported efforts to improve recruitment outcomes. • The CoP model may be adopted by donor recruitment organizations, donor registries, and blood banks worldwide to improve recruitment outcomes.

Hematopoietic Stem Cell Mobilization: Current Collection Approaches, Stem Cell Heterogeneity, and a Proposed New Method for Stem Cell Transplant Conditioning

Hematopoietic stem cells naturally traffic out of their bone marrow niches into the peripheral blood. This natural trafficking process can be enhanced with numerous pharmacologic agents - a process termed "mobilization" - and the mobilized stem cells can be collected for transplantation. We review the current state of mobilization with an update on recent clinical trials and new biologic mechanisms regulating stem cell trafficking. We propose that hematopoietic mobilization can be used to answer questions regarding hematopoietic stem cell heterogeneity, can be used for non-toxic conditioning of patients receiving stem cell transplants, and can enhance gene editing and gene therapy strategies to cure genetic diseases.

Regional Differences Among Bone Marrow Registrants: The Results of a Cross-Sectional Telephone-Based Survey

INTRODUCTION

In the most western and northeastern provincial branches of China where ethnic minorities reside the registry sizes are compatibly small. Our goal was to address the following questions: 1. Do registrants in the 4 regions differ across 4 categories of characteristics associated with decisions to proceed with bone marrow donation? 2. What are the differences in their motivation to attend the CMDP (China Marrow Donor Program)? 3. What possible suggestions could this study supply for the recruitment work of these 4 regions in the future?

MATERIAL AND METHOD

A random sampling procedure was conducted to include 2% of 229,204 newly registered potential bone marrow donors. Participants were contacted to complete a 30-minute structured telephone review.

RESULT

There is a statistically significant effect of region on the causes of donor attrition. For both the opted-out group and ambivalent group of western region registrants, the knowledge (were not fully informed when enrolled) reason was significantly higher than in the other 3 regions. None of the northeast registrants chose "health" as a reason for their ambivalence, in contrast, east registrants had a significantly higher proportion to worry about their health status was not suitable for donation.

DISCUSSION

The results illustrate that in China at least, the mode of registration differs according to the region, which can guide the registry in their retention strategy. The western regions are more likely to be affected by people around and hope to be contacted regularly to confirm the willingness of donation. Interventions that encouraged bone marrow donors to share their experience in their communities might in turn foster an enhanced registration rate. The northeastern regions were more likely to be affected by the newspaper so the media propaganda will be useful for donor recursion. They were also more likely to have questions about the knowledge of bone marrow donation. Continual communication will help registrants secure information to retain favorable beliefs about donation.

Multimedia resources to support the recruitment of committed hematopoietic stem cell donors: Perspectives of the most-needed donors

BACKGROUND

Recruitment of committed unrelated hematopoietic stem cell donors from the most-needed demographics remains a challenge for donor recruitment organizations worldwide. Multimedia resources are gaining attention as a modality to support recruitment efforts; however, there is a lack of guidance for the development of such tools. This qualitative study explores the perspectives of eligible stem cell donors on an educational whiteboard video about stem cell donation, generating insights into how whiteboard videos and related multimedia may be optimized for donor recruitment.

STUDY DESIGN AND METHODS

Eight semistructured focus groups were conducted with 38 potential donors from the most-needed demographics (young, male, and non-Caucasian) after they had watched a 3.5-minute whiteboard video explaining key concepts in stem cell donation (https://youtu.be/V4fVBtxnWfM). Constructivist grounded theory was used to identify themes and to develop a framework for understanding participants' preferred features of recruitment multimedia.

RESULTS

Participants identified a range of features contributing to the effectiveness of recruitment multimedia, adding that the whiteboard video is an effective, integrated, and readily accessible format for supporting donor recruitment. Topics that participants felt are important to address include knowledge gaps regarding donation procedures, concerns about donor safety, and the particular need for specific donor demographics. Suggested avenues for improvement include the addition of donor/recipient/patient personal experiences, attention-grabbing hooks, and a call to action including opportunities for further learning.

CONCLUSIONS

Several considerations were generated to inform the development of future multimedia for donor education/recruitment and are relevant to donor recruitment organizations worldwide.

Factors associated with registrant availability for unrelated adult donor hematopoietic stem cell donation: Analysis of the stem cell registry at Canadian Blood Services

BACKGROUND

Greater use of unrelated donors to support hematopoietic cell transplantation can be hampered by unavailability of registrants when identified as potential candidates for donation.

METHODS

Multivariate analysis was performed to identify donor factors associated with availability for verification of human leukocyte antigen typing (VT) needed before donor activation. All VT requests for registrants on the Canadian Blood Services Stem Cell Registry between 1 January and 31 December 2018 were reviewed (n = 1358).

RESULTS

Potential donors identified by transplant centers were categorized as available at the time of VT but ineligible for medical or other reasons (n = 130 and excluded from further analysis), available (n = 622) or unavailable (n = 566) due to scheduling, loss of interest, and/or inability to contact. With multivariate analysis, registrants who previously donated blood, those recruited online or from blood donation clinics, and a shorter interval between registration and VT request were significantly correlated with increased donor availability. Donor sex and geographic location, however, displayed no correlation.

CONCLUSION

Online registration and recruitment at whole blood donation centers should be enhanced to increase the availability of registrants at VT. More insight is needed to maintain registrant availability following community in-person recruitment events, especially if the interval between registration and activation is prolonged. Recruitment of male registrants who are well informed should not negatively impact availability.

Development and evaluation of stem cell collection procedure diagrams to support the education and recruitment of committed stem cell donors

BACKGROUND

Diagrams which allow potential unrelated stem cell donors to visualize the stem cell collection process were hypothesized to support the recruitment and education of committed stem cell donors.

STUDY DESIGN AND METHODS

A series of bone marrow and peripheral blood stem cell collection procedure diagrams were developed, featuring young adult male donors of varied ethnic backgrounds. Post-implementation, surveys were conducted to evaluate stakeholder perspective on the diagrams' utility. A quality improvement project was conducted at five stem cell drives from 2017 to 2018 at which recruiters did or did not show the diagrams to potential donors. Following the drives, registrants were invited to complete a survey exploring their experience, knowledge and attitude towards donation.

RESULTS

The diagrams were implemented in Canada in 07/2016. Of 293 participating registrants (24·7% non-Caucasian males) recruited at five drives between 2017 and 2018, 76% (n = 197) were shown the diagrams. Participants who were shown the diagrams were significantly more likely to report that the recruiters appeared very knowledgeable (89% vs. 76%, P = 0·019) and to report improved self-reported knowledge of stem cell donation (P = 0·010) compared to participants not shown the diagram. Data are also shown demonstrating that stakeholders in donor recruitment used and valued the diagrams and that use of the diagrams was associated with improved donor recruitment outcomes in Canada.

CONCLUSION

This report is the first evaluation of stem cell collection diagrams in the literature. The diagrams are relevant to donor registries, recruitment organizations and transplant centres worldwide, and their use may support efforts to educate and recruit committed, ethnically diverse donors.