Abstract
Background
The purpose of this study was to determine whether utilization of Hematopoietic Stem Cell Transplantation (HCT) to treat leukemia, lymphoma or multiple myeloma differs by race and gender.
Methods
We estimated the annual incidence of leukemia, lymphoma and multiple myeloma in the United States (US) in people younger than 70 years by race and gender using the SEER Cancer Registry between 1997 and 2002 and US Census Reports for year 2000. The annual incidence of autologous, human leukocyte antigen (HLA) identical sibling and unrelated HCT performed in these groups in the US was estimated using Center for International Blood and Marrow Transplant Research data from 1997 to 2002. Logistic regression was used to calculate the age-adjusted odds ratio of receiving HCT for Caucasians versus African-Americans and men versus women.
Results
The likelihood of undergoing HCT was higher for Caucasians than for African-Americans [Odds Ratio (OR) =1.40 (95%CI: 1.34-1.46)]. This difference existed for each type of HCT: autologous [OR=1.24 (1.19-1.30)], HLA identical sibling [OR=1.59 (1.46-1.74)] and unrelated donor [OR=2.02 (1.75-2.33)]. Overall, men were more likely than women to receive HCT [OR=1.07 (1.05-1.1) p<0.0001]; however, this difference was significant only for autologous HCT [OR=1.10 (1.07-1.13), p<0.0001].
Conclusions
HCT is more frequently used to treat leukemia, lymphoma and multiple myeloma in Caucasians than in African-Americans. African-Americans have lower rates of both autologous and allogeneic HCT, indicating that donor availability cannot fully explain the differences. Women are less likely than men to receive autologous HCT for reasons unexplained by age or disease status.
Keywords: Access to Care, Hematopoietic Stem Cell Transplantation, Effect of race and gender, Leukemia, Lymphoma
Introduction
Hematopoietic stem cell transplantation (HCT) is a relatively new treatment modality. Its history begins in the late 1940's and early 1950's when animal studies revealed the ability of donor bone marrow to restore hematopoiesis after irradiation1. The first successful HCTs in humans were done in 19682-4. Procedure volume has increased rapidly over the last few decades, with approximately 60,000 transplants performed worldwide in 20064. Although HCT has the potential to increase survival for patients with many diseases, particularly hematologic malignancies, it is an intensive, costly, and technically sophisticated procedure with substantial risk of early morbidity and mortality.
Access to healthcare is defined as “the timely use of affordable personal health services to achieve the best possible health outcomes”5. The process of gaining access to care includes dynamic interactions between individuals with diverse ethnic, cultural and socioeconomic backgrounds, healthcare providers operating in a variety of practice patterns with external constraints, and healthcare systems6. HCT is an important treatment option for patients with leukemia, lymphoma and related disorders, offering the best chance for cure in several clinical situations4, 7, 8. Limitations in access to this procedure have substantial clinical, ethical and policy implications.
Considerable variation exists in the distribution of health and healthcare in the United States (US). In 2002, the Institute of Medicine (IOM) published an authoritative report indicating that minorities are less likely than whites to receive needed routine and complex healthcare services across a broad array of diseases including cancer, cardiovascular disease, HIV/AIDS, diabetes and mental illness9. Since that report, the Agency for Healthcare Research and Quality has published an annual National Healthcare Disparities Report [NHDR] to provide an overview of disparities in health care among racial, ethnic and socioeconomic groups in the US, and to track progress in reducing disparities10. The 2006 NHDR suggests that disparities remain prevalent between men and women and among racial groups, including disparities in cancer care11. Several studies indicate men receive more early cancer detection tests than women in the same practices5, 12, 13 and cancer treatment outcomes are poorer in African Americans9-14. Outcome disparities may relate to more advanced stage at diagnosis, a phenomenon thought to be primarily due to underutilization of cancer screening. Some studies suggest that lower socioeconomic status resulting in reduced access to health care may be a major explanation for racial differences in cancer mortality15-25.
The purpose of this study was to determine whether utilization of HCT to treat leukemia, lymphoma or multiple myeloma differs by race and gender. We hypothesized that women and African Americans with these diseases are less likely to receive HCT. While there may be regional differences in healthcare availability26, our study examined utilization rates for the country as a whole.
Research, Design and Methods
The Center for International Blood and Marrow Transplant Research (CIBMTR) database was used to estimate the annual number of HCTs performed in the US between 1997 and 2002. Data from the Surveillance, Epidemiology and End Results (SEER)27, 28 database and the US Census bureau29 were used to estimate the annual total number of new cases of each disease in the US population in the same time-period. Using these data, we estimated the rates (number of transplants/number of patients with disease) of HCT performed for leukemia, lymphoma and multiple myeloma in 1997-2002.
The CIBMTR is a research program formed in July 2004 through an affiliation of the International Bone Marrow Transplant Registry and Autologous Blood and Marrow Transplant Registry of the Medical College of Wisconsin and the National Marrow Donor Program (NMDP). The CIBMTR is a voluntary consortium involving more than 500 transplant centers in 54 countries. These transplant centers worldwide contribute data on consecutive allogeneic and autologous HCTs to CIBMTR. Participating centers are required to report all transplants consecutively and compliance is monitored by on-site audits. Computerized checks for errors, physician review of submitted data, and on-site audits of participating centers ensure the quality of the data. Patients are followed longitudinally, with yearly follow-up. The NMDP facilitates approximately 95% of all unrelated donor HCTs in the United States.
The SEER program of the National Cancer Institute27, 28 is an authoritative source of information on cancer incidence and survival in the United States. The SEER program collects and publishes cancer incidence and survival data from 14 population-based cancer registries and three supplemental registries covering approximately 26% of the US population.
Study population
The population considered for this study included US patients younger than 70 years with acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) treated in 1997-2002; these are the most common disease indications for HCT. Patients older than 70 years were not considered since few transplants are done in older patients.
Analysis
We calculated the annual number of incident cases of ALL, AML, CML, NHL, and MM per 100,000 persons based upon the SEER population sampling frame between 1997 and 2002. First, incidence estimates were calculated from SEER database separately for age group (0-19, 20-29, 30-39, 40-49, 50-59 and 60-69), race (African American and Caucasian) and sex. This incidence rate was then applied to US Census Bureau (year 2000) estimates for numbers of persons in similar age, gender and race groups to derive an estimated annual number of patients with each disease in the US. The estimated annual numbers of autologous, human leukocyte antigen(HLA) identical sibling and unrelated donor HCTs performed during the same time period, and for each gender, race and age group, was calculated by retrieving the number of transplants registered with the CIBMTR from 1997-2002. During this period, the CIBMTR collected an estimated 55% of autologous, 50% of HLA-identical sibling and >90% of unrelated donor HCTs performed in the US (estimation described in more detail elsewhere) 30, 31. Consequently, we applied an adjustment factor of 1.8 and 2.0 to the reported numbers of autologous and HLA-identical sibling HCTs, respectively.
We then evaluated the rates of all HCTs as well as autologous, HLA identical sibling and unrelated donor HCTs by race and gender, for all diagnoses and for each disease separately, using logistic regression analysis adjusting for age. The rates of HCTs were calculated by dividing number of estimated procedures divided by the number of patients diagnosed with disease in the same age range. When multiple comparisons were made, the p-value of significance was considered to be 0.001 or less using bonferroni adjustment.
In these analyses, we assumed that the sample of patients reported to the CIBMTR was representative of the total US population of HCT recipients. A sensitivity analysis was performed to assess the potential effect of selective under-reporting of HCT for African Americans on the results of this study. In the initial analysis, we assumed that 55% of all the autologous HCT and 50% of all the allogeneic HCT performed in the United States were reported to CIBMTR, regardless of race. Data were reanalyzed after increasing the number of autologous and HLA identical sibling transplants for African American reported to CIBMTR by 5%, 10%, 15% and 20%.
Results
A total of 27,725 patients registered with the CIBMTR met our selection criteria. Of these, 15,363 (55%) received autologous HCT, 5731 (21%) received HLA-identical sibling HCT and 6631 (24%) received unrelated donor HCT. There were 25,068 (90%) patients classified as Caucasian and 2,657 (10%) as African American. Fifty-nine percent were males. Pediatric patients only represent 10% of those transplanted, and among those, 81% of transplants were for acute leukemia (AML and ALL). General characteristics of the HCT population are presented in Table 1. Using these data and the adjustment factors described in the Methods, we estimated that there were about 45,750 HCTs done for the eligible diseases during the study period. During the same period of time there were an estimated 273,853 patients diagnosed in the US with the diseases considered in this analysis.
Table 1. Characteristics of HCT Patients.
| Variables | Caucasian N (%)Evaluable | African American N (%) Evaluable | Total N (%) |
|---|---|---|---|
| Number of Patients | 25068(90) | 2657(10) | 27725 |
| Sex | |||
| Male | 14807(59) | 1443(54) | 16250(59) |
| Female | 10261(41) | 1214(46) | 11475(41) |
| Year of Transplant | |||
| 1997 | 3319(13) | 289(11) | 3608(13) |
| 1998 | 3916(16) | 403(15) | 4319(16) |
| 1999 | 4236(17) | 468(18) | 4704(17) |
| 2000 | 4427(18) | 463(17) | 4890(18) |
| 2001 | 4466(18) | 510(19) | 4976(18) |
| 2002 | 4704(19) | 524(20) | 5228(19) |
| Age Group at Transplant | |||
| 0-19 | 2282(9) | 370(14) | 2652(10) |
| 20-29 | 1956(8) | 206(8) | 2162(8) |
| 30-39 | 3261(13) | 406(15) | 3667(13) |
| 40-49 | 5915(24) | 652(25) | 6567(24) |
| 50-59 | 7491(30) | 684(26) | 8175(29) |
| 60-69 | 4163(17) | 339(13) | 4502(16) |
| Donor Type | |||
| Auto HCT | 13758(55) | 1605(60) | 15363(55) |
| HLA sib HCT | 5230(21) | 501(19) | 5731(21) |
| Unrelated HCT | 6080(24) | 551(21) | 6631(24) |
| Disease | |||
| AML | 5247(21) | 458(17) | 5705(21) |
| ALL | 2340(9) | 245(9) | 2585(9) |
| CML | 2824(11) | 341(13) | 3165(11) |
| NHL | 8936(36) | 546(21) | 9482(34) |
| MM | 5721(23) | 1067(40) | 6788(24) |
| Graft Type | |||
| Bone Marrow | 7544(30) | 635(24) | 8179(30) |
| Peripheral Blood | 16985(68) | 1895(71) | 18880(68) |
| Cord Blood | 539 (2) | 127(5) | 666(2) |
Abbreviations: *HCT: Hematopoietic stem cell transplant, AML: acute myelogenous leukemia, ALL: acute lymphoblastic leukemia, CML: chronic myelogenous leukemia, NHL: non-Hodgkin lymphoma, MM: multiple myeloma, Auto: Autologous, HLA Sib: Human leukocyte antigen match sibling
Effect of Race
Overall effect of race
Compared to African Americans, the age-adjusted odds of receiving any type of HCT for all diseases considered was higher for Caucasians [odds ratio (OR) =1.40 (95% confidence intervals, 1.35-1.46), P<0.0001]. A significantly higher odds of receiving HCT was seen for each type of HCT: autologous HCT [OR=1.24 (1.19-1.30), p<0.0001], HLA-identical sibling HCT [OR=1.59 (1.46-1.74), p <0.0001] and unrelated donor HCT [OR=2.02 (1.75-2.33), p <0.0001]. Sensitivity analyses suggest that the results of this study are robust even in the conditional setting of 20% under-reporting of HCTs in African Americans [OR=1.15 (1.10-1.20)]. There were some differences by disease.
Effect of race by disease and type of HCT (Table 2)
Table 2. Age adjusted odds ratio of receiving HCT by race and gender.
| HCT Types and Odds ratios Caucasians vs. African Americans | HCT Types and Odds ratios Males vs. Females | ||||||
|---|---|---|---|---|---|---|---|
| Estimated Annual U.S. incidence | Estimated annual U.S HCTs | Transplant Types | Odds Ratio | p value | Odds Ratio | p value | |
| All Diseases | 45643 | 7623 | Overall HCT | 1.40(1.35-1.46) | <.0001 | 1.07(1.05-1.1) | <.0001 |
| 4608 | Autologous HCT | 1.24(1.19-1.30) | <.0001 | 1.1(1.06-1.13) | <.0001 | ||
| 1910 | HLA Identical Sib HCT | 1.59(1.46-1.74) | <.0001 | 1.05(0.998-1.1) | 0.063 | ||
| 1105 | Unrelated Donor HCT | 2.02(1.75-2.33) | <.0001 | 0.94(0.88-1.01) | 0.11 | ||
| ALL | 3508 | 580 | Overall HCT | 1.01(0.81-1.25) | 0.97 | 1.08(0.96-1.21) | 0.21 |
| 40 | Autologous HCT | 0.74(0.42-1.28) | 0.28 | 0.7(0.49-0.98) | 0.04 | ||
| 262 | HLA Identical Sib HCT | 0.93(0.69-1.24) | 0.61 | 1.17(0.99-1.38) | 0.06 | ||
| 278 | Unrelated Donor HCT | 1.23(0.87-1.73) | 0.24 | 1.08(0.90-1.28) | 0.42 | ||
| AML | 5032 | 1459 | Overall HCT | 1.52(1.35-1.71) | <.0001 | 0.83(0.78-0.88) | <.0001 |
| 363 | Autologous HCT | 1.08(0.90-1.3) | 0.40 | 0.77(0.69-0.85) | <.0001 | ||
| 694 | HLA Identical Sib HCT | 1.44(1.23-1.69) | <.0001 | 0.91(0.83-0.99) | 0.021 | ||
| 402 | Unrelated Donor HCT | 2.29(1.74-3.02) | <.0001 | 0.87(0.77-0.98) | 0.017 | ||
| CML | 2231 | 744 | Overall HCT | 1.42(1.23-1.64) | <.0001 | 0.90(0.82-0.98) | 0.018 |
| 22 | Autologous HCT | 2.36(0.99-5.64) | 0.05 | 1.17(0.77-1.78) | 0.46 | ||
| 413 | HLA Identical Sib HCT | 1.25(1.05-1.49) | 0.01 | 0.89(0.80-0.99) | 0.041 | ||
| 309 | Unrelated Donor HCT | 1.45(1.16-1.81) | 0.001 | 0.92(0.81-1.05) | 0.21 | ||
| NHL | 27960 | 2804 | Overall HCT | 2.12(1.95-2.29) | <.0001 | 1.22(1.17-1.26) | <.0001 |
| 2273 | Autologous HCT | 2.03(1.86-2.22) | <.0001 | 1.18(1.13-1.23) | <.0001 | ||
| 428 | HLA Identical Sib HCT | 2.23(1.78-2.79) | <.0001 | 1.45(1.31-1.60) | <.0001 | ||
| 103 | Unrelated Donor HCT | 3.14(1.79-5.53) | <.0001 | 1.03(0.84-1.27) | 0.77 | ||
| MM | 6912 | 2036 | Overall HCT | 1.75(1.64-1.86) | <.0001 | 1.1(1.05-1.15) | <.0001 |
| 1910 | Autologous HCT | 1.72(1.62-1.83) | <.0001 | 1.1(1.05-1.15) | 0.0001 | ||
| 113 | HLA Identical Sib HCT | 1.55(1.21-1.98) | 0.0006 | 1.03(0.86-1.23) | 0.77 | ||
| 13 | Unrelated Donor HCT | 3.24(1.24-8.50) | 0.016 | 1.64(0.94-2.86) | 0.08 | ||
HCT: Hematopoietic stem cell transplant, AML: acute myelogenous leukemia, ALL: acute lymphoblastic leukemia, CML: chronic myelogenous leukemia, NHL: non-Hodgkin lymphoma, MM: multiple myeloma, Auto: Autologous, HLA Sib: Human leukocyte antigen match sibling
The odds of receiving HCT for MM was higher for Caucasians than for African Americans [OR=1.75(1.64-1.86), p<0.0001]. This difference was seen for autologous HCT [OR=1.72(1.62-1.83), p=<0.0001], HLA identical sibling HCT [OR=1.55(1.21-1.98), p=0.0006], and unrelated donor HCT [OR=3.24(1.24-8.50), p=0.016]. The odds of receiving HCT for NHL was higher for Caucasians than for African Americans [OR=2.12(1.95-2.29), p<0.0001]. This difference was seen for autologous HCT [OR=2.03(1.86-2.22), p<0.0001], HLA identical sibling HCT [OR=2.23(1.89-3.39), and unrelated donor HCT [OR=3.14(1.79-5.53), p<0.0001] p<0.0001]. The odds of receiving HCT for CML was higher for Caucasians than for African Americans [OR=1.42(1.23-1.64), p <0.0001]. This difference was seen for HLA identical sibling HCT [OR=1.25(1.05-1.49), p =0.01] and unrelated donor HCT [OR=1.45(1.16-1.81), p =0.001]. Few patients (n=22) received autologous HCT. The odds receiving HCT for AML was higher for Caucasians than for African Americans [OR=1.52(1.35-1.71), p <0.0001]. This difference was seen for HLA identical sibling HCT [OR=1.44(1.23-1.69, p <0.0001] and unrelated donor HCT [OR=2.29(1.74-3.02), p<0.0001] but not for autologous HCT [OR=1.08(0.90-1.3)]. There was no difference in the odds of receiving HCT for ALL between Caucasians and African Americans [OR=1.01(0.81-1.25), p =0.97].
Effect of Gender
Overall effect of gender
Overall, men were more likely than women to receive HCT [OR=1.07 (1.05-1.1) p<0.0001]; this difference was significant for autologous HCT [OR=1.10 (1.07-1.13), p<0.0001] but not for HLA identical sibling (OR=1.05 (0.99-1.10), p=0.06] or unrelated donor HCT [OR=0.94 (0.88-1.01), p =0.11] and there were important differences by disease. Particularly, men were more likely than women to receive autologous HCT for MM or NHL.
Effect of gender by disease and type of HCT (Table 2)
The odds of receiving HCT for AML was lower for males than females; this difference was significant in all transplant types. The odds of receiving HCT for CML was lower for males than females; this difference was significant for HLA identical sibling HCT but not for autologous or unrelated donor HCT. The odds of receiving HCT for NHL was higher for males than for females; this difference was significant for autologous and HLA identical sibling HCT but not for unrelated donor HCT. The odds of receiving HCT for MM was higher for males than females; this difference was significant for autologous but not for HLA identical sibling or unrelated donor HCT. There was no difference in the odds of receiving HCT for ALL between males and females.
Affect of adult versus pediatric age group
There were 2,652 patients younger than 20 years of age who were registered with the CIBMTR and met our selection criteria in the study period. Most of these children had AML or ALL. We estimated that there were about 2,955 HCTs done for the eligible diseases during the study period. During the same period of time there were an estimated 18,595 patients younger than 20 years of age diagnosed in the US with the diseases considered in this analysis. There were no significant differences by race and gender to report (data not shown) for this age group.
Interaction of Gender and race
We tested for interactions between gender and race by comparing the overall and disease-specific odds of receiving HCT in males versus females adjusting for race, and by comparing the odds of HCT in Caucasians versus African- Americans, adjusting for gender. No significant interactions were evident.
Discussion
Decision-making regarding performance of HCT involves a complex interplay of factors. In general, categories of factors which may explain disparities in applied therapy include biologic factors (intrinsic variability in disease natural history or response to therapy), patient-level factors (presence of co-morbidities that prevent application of therapy and patient preferences), healthcare systems level factors (health insurance and availability of health care facilities), care process or discrimination factors (provider attitudes such as bias against minorities, greater clinical uncertainty when understanding minorities symptoms and severity, or pre-conceived beliefs regarding minority behavior or health). Ideally, clinical needs and appropriateness, biologic factors, and patient preferences should be the only considerations driving the therapeutic decision-making process. We assume that patient-related (other than preferences) and disease-related clinical factors do not vary by race and gender such that indications for HCT are not dramatically different in different race and gender groups. We believe this is a reasonable assumption based on what is known about the diseases included in these analyses. Our findings suggest a disparity in the rates of autologous and allogeneic HCT for African Americans and females that should cause concern, with the greatest disparity observed by race. The rates of HCT were higher in Caucasians than in African-Americans in almost all subgroups examined, with odds ratios higher than 2 in some categories.
Disparity in care could represent either under-utilization in African-Americans, or overutilization in Caucasians. It could also be attributed to biologic differences. For example, the greater distribution of HLA types in African-Americans and the smaller number of African Americans on volunteer donor registries makes it more difficult to find a suitably matched donor for African Americans in need of unrelated donor HCT. This may contribute to the lower rate of unrelated donor HCTs in this group. However, multiple myeloma is a common indication for HCT. The preferred type of HCT for this disease is autologous, and during the 5 year time period spanned by this study it became the most common indication for autologous HCT31. MM is twice more common in African Americans than in Caucasians but the odds of receiving an HCT for MM were 72% higher for Caucasians. These lower rates of autologous HCT suggest that the disparity is best explained by under-utilization of HCT in African Americans and cannot be wholly attributed to donor availability.
The disparity in use of HCT in men in women is less consistent than the disparity in use by race, with odds ratios closer to one and increased odds in men in some diseases and in women in others. A unifying hypothesis for these differences is difficult to devise.
There were no significant differences in access to HCT for children by gender or race. The lack of differential access to HCT for children compared to adults may be attributed, in part, to better governmental (including state gap programs) and private insurance for children than adults. Additionally, a larger percentage of children, particularly those with acute leukemia, are referred early in their treatment course to larger pediatric medical centers and are treated on cooperative group trials which may be more likely to afford them access to HCT.
Limitations
Several limitations should be considered. This analysis takes a national perspective in considering racial disparities in HCT. CIBMTR collected data on approximately 55% of all autologous transplants and 50% related donor transplants performed annually in the US during the time period included in this study. Although regional differences may be of greater interest since referral for HCT generally occurs on a local/regional basis, the nature of the SEER and CIBMTR databases preclude sub-analyses to present regional differences in HCT. It is also possible that centers that do more related donor or autologous transplants in African Americans are under-represented in the CIBMTR. We addressed this incomplete denominator of US transplant activity by performing sensitivity analysis, the results of which suggest that our conclusions are robust up to a moderate (20%) level of underreporting for specific racial groups. Since CIBMTR captures data on almost all unrelated donor transplants in the US, potential biases in reporting are not an issue for that type of HCT and, in fact, disparities in utilization were highest for unrelated donor HCT.
An additional consideration is that attribution of race of patients in the CIBMTR observational database is provided by the transplant centers. Centers may not use homogenous processes to identify and report the race of HCT recipients; these designations may not match self-reported race and may contribute to reporting bias. However, it seems likely that reporting of race within the SEER database during the same time period would be subject to very similar biases, given the similarities in reporting method between the two databases. If individuals from a particular race were systematically misclassified in any of these databases, it may misrepresent the true access rate for that race.
We assumed that family sizes, and therefore number of potential sibling donors, were equal between African-American and Caucasian populations. Because the CIBMTR only collects data on HCT recipients, we were unable to explore whether differences exist between gender and racial groups in rates of referral for consideration of HCT. Biologic-based racial differences in clinical presentation or response to initial therapy for disease may represent partial explanation of disparity in HCT rates. Unfortunately, we did not have sufficient data regarding disease status at diagnosis or comorbidities to determine whether this may have affected consideration of HCT as a treatment option. Although for the purposes of these analyses we have assumed that clinical appropriateness of HCT is similar across the groups studied as described above, other studies have suggested that African Americans are more likely to be diagnosed with advanced stage disease than whites, which would make them more likely candidates for aggressive therapy for their advanced diseases32-34. However, if true, such differences in stage at diagnosis should serve to increase, not decrease, the odds of HCT among African Americans compared to Caucasians.
No data are available regarding patient preferences for treatment, rates of refusal of HCT, or other sociocultural factors that could explain differences in HCT seen in this study. Finally, there were insufficient data regarding health care process factors such as referring provider and transplant physician characteristics and practice patterns, geographic referral patterns, transplant center characteristics or socioeconomic characteristics of the patient to be incorporated into these analyses.
Conclusions
We observed a difference in utilization of HCT for leukemia, lymphoma and multiple myeloma by race, with Caucasians more likely to receive HCT than African-Americans. Importantly, lower HCT rates for African-Americans were seen for autologous HCT, indicating that donor availability cannot fully explain the differences. Differences by gender were less striking. We believe these differences represent substantial under-utilization of HCT in African Americans. Identification of disparities should serve as the motivation to further understand their cause, and their elimination whenever they are inappropriate. Further study is essential to better characterize and explain disparities in access to HCT. Research should explore whether patient or provider preferences, sociocultural or socioeconomic factors, or health care process factors explain disparities in access to HCT, and whether these factors are modifiable. While waiting for further research to better understand disparate access to HCT, the medical community should work at all levels to eliminate these disparities.
Acknowledgments
Center for International Blood and Marrow Transplant Research (CIBMTR)
Support List: The CIBMTR is supported by Public Health Service Grant/Cooperative Agreement U24-CA76518 from the National Cancer Institute (NCI), the National Heart, Lung and Blood Institute (NHLBI) and the National Institute of Allergy and Infectious Diseases (NIAID); a Grant/Cooperative Agreement 5U01HL069294 from NHLBI and NCI; a contract HHSH234200637015C with Health Resources and Services Administration (HRSA/DHHS); two Grants N00014-06-1-0704 and N00014-08-1-0058 from the Office of Naval Research; and grants from AABB; Aetna; American Society for Blood and Marrow Transplantation; Amgen, Inc.; Anonymous donation to the Medical College of Wisconsin; Astellas Pharma US, Inc.; Baxter International, Inc.; Bayer HealthCare Pharmaceuticals; Be the Match Foundation; Biogen IDEC; BioMarin Pharmaceutical, Inc.; Biovitrum AB; BloodCenter of Wisconsin; Blue Cross and Blue Shield Association; Bone Marrow Foundation; Canadian Blood and Marrow Transplant Group; CaridianBCT; Celgene Corporation; CellGenix, GmbH; Centers for Disease Control and Prevention; Children's Leukemia Research Association; ClinImmune Labs; CTI Clinical Trial and Consulting Services; Cubist Pharmaceuticals; Cylex Inc.; CytoTherm; DOR BioPharma, Inc.; Dynal Biotech, an Invitrogen Company; Eisai, Inc.; Enzon Pharmaceuticals, Inc.; European Group for Blood and Marrow Transplantation; Gamida Cell, Ltd.; GE Healthcare; Genentech, Inc.; Genzyme Corporation; Histogenetics, Inc.; HKS Medical Information Systems; Hospira, Inc.; Infectious Diseases Society of America; Kiadis Pharma; Kirin Brewery Co., Ltd.; The Leukemia & Lymphoma Society; Merck & Company; The Medical College of Wisconsin; MGI Pharma, Inc.; Michigan Community Blood Centers; Millennium Pharmaceuticals, Inc.; Miller Pharmacal Group; Milliman USA, Inc.; Miltenyi Biotec, Inc.; National Marrow Donor Program; Nature Publishing Group; New York Blood Center; Novartis Oncology; Oncology Nursing Society; Osiris Therapeutics, Inc.; Otsuka America Pharmaceutical, Inc.; Pall Life Sciences; Pfizer Inc; Saladax Biomedical, Inc.; Schering Corporation; Society for Healthcare Epidemiology of America; StemCyte, Inc.; StemSoft Software, Inc.; Sysmex America, Inc.; Teva Pharmaceutical Industries;; THERAKOS, Inc.; Thermogenesis Corporation; Vidacare Corporation; Vion Pharmaceuticals, Inc.; ViraCor Laboratories; ViroPharma, Inc.; and Wellpoint, Inc. The views expressed in this article do not reflect the official policy or position of the National Institute of Health, the Department of the Navy, the Department of Defense, or any other agency of the U.S. Government.
Footnotes
Financial Disclosures from any author: None
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