"Don't keep me waiting": estimating the impact of reduced vein-to-vein time on lifetime US 3L+ LBCL patient outcomes.

ABSTRACT: Chimeric antigen receptor T-cell therapy (CAR T) has revolutionized the treatment of hematological cancers. Its production requires a complex logistical process, and the time from leukapheresis to patient infusion (known as the vein-to-vein time [V2VT]) can be long during which a patients clinical condition may deteriorate. This study was designed to estimate the benefits of reduced V2VT for third-line or later (3L+) relapsed/refractory large B-cell lymphoma (R/R LBCL) patients treated with CAR T. A mathematical model was developed to estimate the lifetime outcomes of a hypothetical cohort of patients who had either a long or short V2VT. Life-years (LYs), quality-adjusted LYs (QALYs), and costs were estimated. Scenario analyses were performed to assess the robustness of results to key assumptions. The results of the model show that reducing V2VT from 54 days (tisa-cel median V2VT; JULIET) to 24 days (axi-cel median V2VT; ZUMA-1) led to a 3.2-year gain in life expectancy (4.2 vs 7.7 LYs), and 2.4 additional QALYs (3.2 vs 5.6) per patient. Furthermore, a shorter V2VT was shown to be cost-effective under conventional willingness-to-pay thresholds in the United States. Results are driven by a higher infusion rate and a better efficacy of CAR T for those infused. Scenario analyses using a smaller difference in V2VT (24 vs 36 days) produced consistent results. Our study is the first to quantify lifetime V2VT-related outcomes for 3L+ R/R LBCL patients treated with CAR T utilizing currently available evidence. Shorter V2VTs led to improved outcomes, demonstrating the importance of timely infusion achievable by faster manufacturing times and optimization of hospital delivery.

International harmonization in performing and reporting minimal residual disease assessment in multiple myeloma trials.

Minimal residual disease (MRD) assessment is incorporated in an increasing number of multiple myeloma (MM) clinical trials as a correlative analysis, an endpoint or even as a determinant of subsequent therapy. There is substantial heterogeneity across clinical trials in how MRD is assessed and reported, creating challenges for data interpretation and for the design of subsequent studies. We convened an international panel of MM investigators to harmonize how MRD should be assessed and reported in MM clinical trials. The panel provides consensus on which MM trials should include MRD, the recommended time points for MRD assessment, and expected analytical validation for MRD assays. We subsequently outlined parameters for reporting MRD results implementing the intention-to-treat principle. The panel provides guidance regarding the incorporation of newer peripheral blood-based and imaging-based approaches to detection of residual disease. Recommendations are summarized in 13 consensus statements that should be followed by sponsors, investigators, editors, and reviewers engaged in designing, performing, and interpreting MM trials.

The Global State of Hematopoietic Cell Transplantation for Multiple Myeloma: An Analysis of the Worldwide Network of Blood and Marrow Transplantation Database and the Global Burden of Disease Study.

Multiple myeloma (MM) is a plasma cell neoplasm characterized by destructive bony lesions, anemia, and renal impairment. Access to effective therapy is limited globally. We report the rates and utilization of hematopoietic cell transplantation (HCT) globally from 2006-2015 to better characterize access to HCT for patients with MM. This was an analysis of a retrospective survey of Worldwide Network of Blood and Marrow Transplant sites, conducted annually between 2006-2015. Incidence estimates were from the Global Burden of Disease study. Outcome measures included total number of autologous and allogeneic HCTs by world regions, and percentage of newly diagnosed MM patients who underwent HCT, calculated by the number of transplants per region in calendar year/gross annual incidence of MM per region. From 2006 to 2015, the number of autologous HCT performed worldwide for MM increased by 107%. Utilization of autologous HCT was highest in Northern America and European regions, increasing from 13% to 24% in Northern America, and an increase from 15% to 22% in Europe. In contrast, the utilization of autologous HCT was lower in the Africa/Mediterranean region, with utilization only changing from 1.8% in 2006 to 4% in 2015. The number of first allogeneic HCT performed globally for MM declined after a peak in 2012 by -3% since 2006. Autologous HCT utilization for MM has increased worldwide in high-income regions but remains poorly utilized in Africa and the East Mediterranean. More work is needed to improve access to HCT for MM patients, especially in low to middle income countries. © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Utilization and Cost Implications of Hematopoietic Progenitor Cells Stored for a Future Salvage Autologous Transplantation or Stem Cell Boost in Myeloma Patients.

Autologous hematopoietic cell transplantation (autoHCT) is a standard initial treatment for multiple myeloma (MM). Consensus guidelines recommend collecting sufficient hematopoietic progenitor cells (HPCs) for 2 autoHCTs in all eligible patients. Despite a lack of published data on the utilization of HPCs stored for future use, it is common practice across transplantation programs to collect enough HPCs for 2 autoHCTs in MM patients. In this single-center retrospective study, we analyzed the utilization of HPCs collected and stored at the time of first autoHCT in patients with MM, along with the cost implications of HPC collection targets sufficient for 2 transplantations. In a cohort of 400 patients (median age, 63 years; range, 22 to 79 years), after a median follow-up of 50.4 months, 197 patients had relapsed and 36 had received HPC infusion as salvage autoHCT (n = 29) and/or HPC boost (n = 8). In this cohort, a median CD34+ cell dose of 4.3 × 106/kg (range, 1.1 to 12.94.3 × 106/kg) was used for first autoHCT, and a median of 4.4 × 106/kg (range, 1.0 to 20.2× 106/kg) CD34+ cells were stored for future use. At 6 years after the first autoHCT, the estimated cumulative incidence of salvage autoHCT was 12.0% without HPC boost and 13.9% with HPC boost. HPC utilization was significantly higher in the 60- to 64-year age group, whereas no patients who were age ≥70 years at the time of first autoHCT received salvage autoHCT. Using the CD34+ cell dose infused during the first autoHCT as the cutoff for individual patients, the estimated mean additional cost of HPC collection intended for subsequent use (over and above the HPCs used for first autoHCT) was $10,795 ($4.32 million for the entire cohort), an estimated 14% of which (ie, $583,600) was actually used up in salvage autoHCT by 6 years from first autoHCT. In conclusion, our results suggest the need for reappraisal of HPC collection targets for salvage autoHCT and argue against HPC collection and storage for salvage autoHCT in patients age ≥70 years at the time of first autoHCT.

Geriatric assessment in older alloHCT recipients: association of functional and cognitive impairment with outcomes.

Use of allogeneic hematopoietic cell transplantation (alloHCT) is increasing in older patients with hematologic malignancies. Studies suggest that geriatric assessment (GA), incorporating functional measures such as instrumental activities of daily living (IADL), delineates subtle age-related impairments that enhance risk-stratification. The objective of this multi-institutional retrospective study was to evaluate the prognostic utility of GA metrics collected pre-alloHCT. Eligibility criteria included age ≥50 and pre-alloHCT GA inclusive of at least IADL. Beyond IADL, additional geriatric metrics were collected where available and included Medical Outcomes Study Physical Health score (MOS-PH), Timed Up and Go (TUG), and cognition by Blessed Orientation Memory Concentration (BOMC). Three hundred thirty subjects were included, with a median age of 63 (range 50 to 77). Impairments were frequent: 36% had at least 1 IADL impairment; 14% had TUG ≥13.5 seconds; and 17% had cognitive impairment (BOMC ≥ 7). Median MOS-PH score was 80. IADL and age were not significantly associated with nonrelapse mortality (NRM) or overall survival (OS). In multivariate analysis, only impaired cognition and Hematopoietic Cell Transplant-Comorbidity Index score ≥3 showed an independent association with 1-year NRM (subdistribution hazard ratio [SHR], 2.36; P = .01; and SHR, 2.19; P = .009, respectively). Cognitive impairment independently conferred inferior 1-year OS (hazard ratio, 1.94; P = .01). In a preplanned subgroup analysis in 224 patients aged ≥60 years, cognitive impairment remained the sole GA metric predictive of NRM (2-year NRM: SHR, 2.72; P = .007). These data suggest that cognitive impairment elevates risk of post-alloHCT NRM in older patients.

Factors Associated With Unplanned 30-Day Readmissions After Hematopoietic Cell Transplantation Among US Hospitals.

Importance: Hematopoietic cell transplantation (HCT) is a therapeutic strategy in the management of several hematological cancers. Limited data exist on the incidence and predictors of 30-day readmission after HCT. Objective: To measure the incidence of and risk factors associated with 30-day readmission following HCT in the United States. Design, Setting, and Participants: This cohort study examined patient data from the US population-based Nationwide Readmissions Database. All adults (age ≥18 years) who underwent autologous (auto-) or allogenic (allo-) HCT in US hospitals between January 1, 2012, and November 30, 2014, were included. The analysis was performed from June 2018 to February 2019. Main Outcomes and Measures: The main outcome was 30-day readmission rates for auto-HCT and allo-HCT. Factors associated with readmission, including baseline demographic characteristics and disease- and hospital-related characteristics (including annual case volume), were measured. Results: A total of 28 356 index admissions for auto-HCT in 244 centers (191 low-volume, 38 medium-volume, and 15 high-volume centers) and 17 217 index admissions for allo-HCT in 211 centers (161 low-volume, 37 medium-volume, and 13 high-volume centers) were identified during the study period. The overall 30-day readmission rates were 11.6% for auto-HCT and 24.4% for allo-HCT. The odds of readmission were significantly higher in low-volume hospitals compared with high-volume hospitals (adjusted odds ratio [aOR], 1.69; 95% CI, 1.08-2.64 for auto-HCT and aOR, 1.41; 95% CI, 1.09-1.82 for allo-HCT) but comparable to medium-volume hospitals (aOR, 1.06; 95% CI, 0.62-1.83 for auto-HCT and aOR, 1.19; 95% CI, 0.90-1.57 for allo-HCT). Other factors associated with readmission for auto-HCT included younger age (aOR for age ≥50 vs <49 years, 0.82; 95% CI, 0.68-0.98), female sex (aOR, 1.21; 95% CI, 1.06-1.36), disease type (aOR for other vs myeloma, 1.37; 95% CI, 1.06-1.77), and Elixhauser comorbidity index score (aOR for ≥20 vs 0, 1.5; 95% CI, 1.17-1.93). For allo-HCT, factors associated with readmission included disease type (aOR for acute lymphoblastic leukemia vs acute myelogenous leukemia, 1.30; 95% CI, 1.04-1.62), insurance (aOR for Medicare vs private, 1.18; 95% CI, 1.02-1.36), and Elixhauser comorbidity index score (aOR for 1-9 vs 0, 1.2; 95% CI, 1.04-1.39). Infections, neutropenic fever, and gastrointestinal symptoms were the most common reasons for readmission for both types of HCT. Conclusions and Relevance: This study found substantial rates of readmission for both types of HCT and an inverse association between hospital HCT volume and 30-day readmission. These results may provide guidance when developing quality indicators and policies penalizing hospitals for HCT readmission.

Worldwide Network for Blood and Marrow Transplantation Recommendations for Establishing a Hematopoietic Stem Cell Transplantation Program in Countries with Limited Resources, Part II: Clinical, Technical, and Socioeconomic Considerations.

The development of hematopoietic stem cell transplantation (HSCT) programs can face significant challenges in most developing countries because such endeavors must compete with other government health care priorities, including the delivery of basic services. Although this is may be a limiting factor, these countries should prioritize development of the needed expertise to offer state-of-the-art treatments, including transplantation, by providing financial, technological, legal, ethical, and other needed support. This would prove beneficial in providing successful programs customized to the needs of their population and potentially provide long-term cost savings by circumventing the need for their citizens to seek care abroad. The costs of establishing an HSCT program and the costs of the HSCT procedure itself can be substantial barriers in developing countries. In addition, socioeconomic factors intrinsic to specific countries can influence access to HSCT, patient eligibility for HSCT, and timely utilization of HSCT center capabilities. This report describes recommendations from the Worldwide Network for Blood and Marrow Transplantation for establishing HSCT programs, with a specific focus on developing countries, and identifies challenges and opportunities for providing this specialized procedure in resource-constrained settings.

Comparison of Graft Acquisition and Early Direct Charges of Haploidentical Related Donor Transplantation versus Umbilical Cord Blood Transplantation.

Alternative donor allogeneic hematopoietic cell transplants (HCTs), such as double umbilical cord blood transplants (dUCBT) and haploidentical related donor transplants (haplo-HCT), have been shown to be safe and effective in adult patients who do not have an HLA-identical sibling or unrelated donor available. Most transplant centers have committed to 1 of the 2 alternative donor sources, even with a lack of published randomized data directly comparing outcomes and comparative data on the cost-effectiveness of dUCBT versus haplo-HCT. We conducted a retrospective study to evaluate and compare the early costs and charges of haplo-HCT and dUCBT in the first 100 days at 2 US transplant centers. Forty-nine recipients of haplo-HCT (at 1 center) and 37 with dUCBT (at another center) were included in the analysis. We compared graft acquisition, inpatient/outpatient, and total charges in the first 100 days. The results of the analysis showed a significantly lower cost of graft acquisition and lower total charges (for 100-day HCT survivors) in favor of haplo-HCT. Importantly, to control for the obvious shortcomings of comparing costs at 2 different transplant centers, adjustments were made based on the current (2018) local wage index and inflation rate. In the absence of further guidance from a prospective study, the cost analysis in this study suggests that haplo-HCT may result in early cost savings over dUCBT and may be preferred by transplant centers and for patients with more limited resources.

Cost and quality issues in establishing hematopoietic cell transplant program in developing countries.

The hematopoietic cell transplant (HCT) activity has grown significantly over the past two decades in both developing and developed countries. Many challenges arise in establishing new HCT programs in developing countries, due to scarcity of resources and manpower in expertise in HCT. While cost issues can potentially hinder establishment of new HCT programs in certain regions, the focus on quality and value should be included in the general vision of leadership before establishing an HCT program. The main challenge in most developing countries is the lack of trained/qualified personnel, enormous start-up costs for a tertiary care center, and quality maintenance. Herein, we discuss the main challenges from a cost and quality perspective which occur at initiation of a new HCT program. We give real world examples of two developing countries that have recently started new HCT programs despite significant financial constraints. We also portray recommendations from the Worldwide Network of Blood and Marrow Transplantation for levels of requirements for a new HCT program. We hope that this review will serve as a general guide for new transplant program leadership with respect to the concerns of balancing high quality with concurrently lowering costs.

Hematopoietic Progenitor Cell Mobilization with Ifosfamide, Carboplatin, and Etoposide Chemotherapy versus Plerixafor-Based Strategies in Patients with Hodgkin and Non-Hodgkin Lymphoma.

Studies comparing the efficacy and safety of chemo-mobilization with ifosfamide, carboplatin, and etoposide (ICE) ± rituximab with plerixafor-based approaches in lymphoma patients have not been performed. We analyzed hematopoietic progenitor cell mobilization outcomes in lymphoma patients undergoing chemo-mobilization with ICE (n = 35) compared with either routine plerixafor (n = 30) or "just in time" (JIT) plerixafor-based mobilization (n = 33). Chemo-mobilization provided a significantly higher total CD34(+) cell yield (median collection, 5.35 × 10(6) cells/kg for ICE versus 3.15 × 10(6) cells/kg for routine plerixafor and 3.6 × 10(6) cells/kg for JIT plerixafor, P < .001). The median day 1 yield of CD34(+) cells was not significantly different (median, 2.2 × 10(6) cells/kg in ICE versus 1.9 × 10(6) cells/kg in upfront plerixafor versus 1.7 × 10(6) cells/kg in JIT plerixafor, P = .20). There was no significant difference in the 3 groups in terms of total number of apheresis sessions performed (median, 2 in each group; P = .78). There were no mobilization failures (inability to collect at least 2 × 10(6) cells/kg) in the chemo-mobilization group, whereas 5 patients (16.7%) in the routine plerixafor and 3 patients (9.1%) in JIT group had mobilization failure (P = .04). Mean time to neutrophil engraftment was faster in the chemo-mobilization group, 10.3 days (±1.2) compared with 12.1 days (±3.6) in the routine plerixafor group and 11.6 days (±3.0) in the JIT group (P < .001) and mean time to platelet engraftment was 13.7 days (±.7) in ICE versus 20.3 days (±1.6) in routine plerixafor versus 17.1 days (± .9) in JIT group (P < .001). Red blood cell transfusions were significantly higher in the chemo-mobilization group (34.3% versus 0 versus 3.2% versus 1, P < .001) and so were the platelet transfusions (22.9% versus 0 versus 0, P < .001). Excluding the cost of chemotherapy administration, chemo-mobilization was associated with significantly less mobilization cost (average cost $17,601.76 in ICE versus $28,963.05 in routine and $25,679.81 in JIT, P < .001). Our data suggests that chemo-mobilization with ICE provides a higher total CD34(+) cell yield, lower rates of mobilization failure, faster engraftment, and lower cost compared to plerixafor-based approaches with comparable toxicity profile between the groups, except for higher transfusion requirements with chemo-mobilization.

Comparing Outcomes with Bone Marrow or Peripheral Blood Stem Cells as Graft Source for Matched Sibling Transplants in Severe Aplastic Anemia across Different Economic Regions.

Bone marrow (BM) is the preferred graft source for hematopoietic stem cell transplantation (HSCT) in severe aplastic anemia (SAA) compared with mobilized peripheral blood stem cells (PBSCs). We hypothesized that this recommendation may not apply to those regions where patients present later in their disease course, with heavier transfusion load and with higher graft failure rates. Patients with SAA who received HSCT from an HLA-matched sibling donor from 1995 to 2009 and reported to the Center for International Blood and Marrow Transplant Research or the Japan Society for Hematopoietic Cell Transplantation were analyzed. The study population was categorized by gross national income per capita and region/countries into 4 groups. Groups analyzed were high-income countries (HIC), which were further divided into United States-Canada (n = 486) and other HIC (n = 1264); upper middle income (UMIC) (n = 482); and combined lower-middle, low-income countries (LM-LIC) (n = 142). In multivariate analysis, overall survival (OS) was highest with BM as graft source in HIC compared with PBSCs in all countries or BM in UMIC or LM-LIC (P < .001). There was no significant difference in OS between BM and PBSCs in UMIC (P = .32) or LM-LIC (P = .23). In LM-LIC the 28-day neutrophil engraftment was higher with PBSCs compared with BM (97% versus 77%, P = .002). Chronic graft-versus-host disease was significantly higher with PBSCs in all groups. Whereas BM should definitely be the preferred graft source for HLA-matched sibling HSCT in SAA, PBSCs may be an acceptable alternative in countries with limited resources when treating patients at high risk of graft failure and infective complications.

Guidelines for defining and implementing standard episode of care for hematopoietic stem cell transplantation within the context of clinical trials.

The Patient Protection and Affordable Care Act requires that health care insurers cover routine patient costs associated with participating in clinical trials for cancer and other life-threatening diseases. There is a need to better define routine costs within the context of hematopoietic stem cell transplantation (HSCT) clinical trials. This white paper presents guidance on behalf of the American Society for Blood and Marrow Transplantation for defining a standard HSCT episode and delineates components that may be considered as routine patient costs versus research costs. The guidelines will assist investigators, trial sponsors, and transplantation centers in planning for clinical trials that are conducted as a part of the HSCT episode and will inform payers who provide coverage for transplantation.

Recommendations for donor human leukocyte antigen assessment and matching for allogeneic stem cell transplantation: consensus opinion of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN).

The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) conducts large, multi-institutional clinical trials with the goal of improving the outcomes of hematopoietic cell transplantation (HCT) for patients with life-threatening disorders. Well-designed HCT trials benefit from standardized criteria for defining diagnoses, treatment plans, and graft source selection. In this perspective, we summarize evidence supporting criteria for the selection of related and unrelated adult volunteer progenitor cell donors or umbilical cord blood units. These standardized criteria for graft source selection have been adopted by the BMT CTN to enhance the interpretation of clinical findings within and among future clinical protocols.

Quantitative and qualitative differences in use and trends of hematopoietic stem cell transplantation: a Global Observational Study.

Fifty-five years after publication of the first hematopoietic stem cell transplantation this technique has become an accepted treatment option for defined hematologic and non-hematologic disorders. There is considerable interest in understanding differences in its use and trends on a global level and the macro-economic factors associated with these differences. Data on the numbers of hematopoietic stem cell transplants performed in the 3-year period 2006-2008 were obtained from Worldwide Network for Blood and Marrow Transplantation member registries and from transplant centers in countries without registries. Population and macro-economic data were collected from the World Bank and from the International Monetary Fund. Transplant rates were analyzed by indication, donor type, country, and World Health Organization regional offices areas and related to selected health care indicators using single and multiple linear regression analyses. Data from a total of 146,808 patients were reported by 1,411 teams from 72 countries over five continents. The annual number of transplants increased worldwide with the highest relative increase in the Asia Pacific region. Transplant rates increased preferentially in high income countries (P=0.02), not in low or medium income countries. Allogeneic transplants increased for myelodysplasia, chronic lymphocytic leukemia, acute leukemias, and non-malignant diseases but decreased for chronic myelogenous leukemia. Autologous transplants increased for autoimmune and lymphoproliferative diseases but decreased for leukemias and solid tumors. Transplant rates (P<0.01), donor type (P<0.01) aand disease indications (P<0.01) differed significantly between countries and regions. Transplant rates were associated with Gross National Income/capita (P<0.01) but showed a wide variation of explanatory content by donor type, disease indication and World Health Organization region. Hematopoietic stem cell transplantation activity is increasing worldwide. The preferential increase in high income countries, the widening gap between low and high income countries and the significant regional differences suggest that different strategies are required in individual countries to foster hematopoietic stem cell transplantation as an efficient and cost-effective treatment modality.

Hematopoietic cell transplantation for chronic myeloid leukemia in developing countries: perspectives from Latin America in the post-tyrosine kinase inhibitor era.

Tyrosine kinase inhibitors (TKIs) are currently the first line treatment for chronic myelogenous leukemia (CML) in countries with high and intermediate-high gross national income. Hematopoietic cell transplantation (HCT) in these countries is considered salvage therapy for eligible patients who failed TKI or progress to advanced disease stages. In Latin America, treatment for CML also changed with availability of TKI in the region. However, many challenges remain, as the cost of this class of medication and recommended monitoring is high. CML treatment practices in Latin America demonstrate that the majority of patients are treated with TKI at some point after diagnosis, most commonly imatinib mesylate, but still TKI can only be used after interferon failure in some countries. Other treatment practices are different from established international guidelines, outlying the importance of continuing medical education. Allogeneic HCT is a treatment option for CML in this region and could be considered a cost-effective approach in a small subset of young patients with available donors, as the overall cost of long-term non-transplant treatment may surpass the cost of transplantation. However, there are many challenges with HCT in Latin America such as access to experienced transplant centers, donor availability, and cost of essential drugs used after transplant, which further impacts expansion of this treatment approach in patients in need. In conclusion, Latin American patients with CML have access to state of the art CML treatment. Yet, drug costs have a tremendous impact on developing health systems. Optimization of CML treatment in the region with appropriate monitoring, recognizing patients who would be transplant candidates, and expanding access to transplantation for eligible patients may curtail these costs and further improve patient care.

Hematopoietic stem cell transplantation: a global perspective.

CONTEXT: Hematopoietic stem cell transplantation (HSCT) requires significant infrastructure. Little is known about HSCT use and the factors associated with it on a global level. OBJECTIVES: To determine current use of HSCT to assess differences in its application and to explore associations of macroeconomic factors with transplant rates on a global level. DESIGN, SETTING, AND PATIENTS: Retrospective survey study of patients receiving allogeneic and autologous HSCTs for 2006 collected by 1327 centers in 71 participating countries of the Worldwide Network for Blood and Marrow Transplantation. The regional areas used herein are (1) the Americas (the corresponding World Health Organization regions are North and South America); (2) Asia (Southeast Asia and the Western Pacific Region, which includes Australia and New Zealand); (3) Europe (includes Turkey and Israel); and (4) the Eastern Mediterranean and Africa. MAIN OUTCOME MEASURES: Transplant rates (number of HSCTs per 10 million inhabitants) by indication, donor type, and country; description of main differences in HSCT use; and macroeconomic factors of reporting countries associated with HSCT rates. RESULTS: There were 50 417 first HSCTs; 21 516 allogeneic (43%) and 28 901 autologous (57%). The median HSCT rates varied between regions and countries from 48.5 (range, 2.5-505.4) in the Americas, 184 (range, 0.6-488.5) in Asia, 268.9 (range, 5.7-792.1) in Europe, and 47.7 (range, 2.8-95.3) in the Eastern Mediterranean and Africa. No HSCTs were performed in countries with less than 300,000 inhabitants, smaller than 960 km(2), or having less than US $680 gross national income per capita. Use of allogeneic or autologous HSCT, unrelated or family donors for allogeneic HSCT, and proportions of disease indications varied significantly between countries and regions. In linear regression analyses, government health care expenditures (r(2) = 77.33), HSCT team density (indicates the number of transplant teams per 1 million inhabitants; r(2) = 76.28), human development index (r(2) = 74.36), and gross national income per capita (r(2) = 74.04) showed the highest associations with HSCT rates. CONCLUSION: Hematopoietic stem cell transplantation is used for a broad spectrum of indications worldwide, but most frequently in countries with higher gross national incomes, higher governmental health care expenditures, and higher team densities.