Impact of donor deferrals for malaria on blood availability in the United States

BACKGROUND: US blood availability is negatively impacted by residence or travel‐related deferrals designed to prevent transmission of human immunodeficiency virus type 1 group O, variant Creutzfeldt‐Jakob disease, Leishmania, and malaria. Generally, travel and residence deferrals lack sensitivity and specificity to identify infected donors, particularly for malaria. This study evaluated trends in malaria deferrals and their impact on blood availability from 2000 through 2006. STUDY DESIGN AND METHODS: An American Red Cross (ARC) research database was used to monitor trends in deferrals for exposure to Plasmodium spp., the causative agents of malaria. Annual deferral rates were classified as travel, residence, and history of malaria during 2000 through 2006. Overall yearly donation rates for acceptable donors were determined and used to estimate donations lost due to malaria‐related deferrals. RESULTS: Approximately 29 million donors presented at ARC collection sites and 316,495 (1.1%) were deferred for malaria risk. More than 91 percent of malaria deferrals were for travel to endemic countries; travel deferrals showed a significant increase (p < 0.001) throughout the study period. Calculations of yearly donation rates suggested that more than 540,000 potential ARC blood donations were lost to malaria deferrals during the 7‐year period. CONCLUSIONS: The vast majority of malaria deferrals were for travel to endemic areas; however, few US donors visit those areas associated with most US cases of malaria or transfusion‐transmitted malaria. Current interventions fail to capture many semi‐immune donors, those at greatest risk for transmitting infection. Considerations should be given to selective screening and permanent deferral of donors with a history of malaria.     

Donor deferral and resulting donor loss at the American Red Cross Blood Services, 2001 through 2006

BACKGROUND: A large number of blood donors are deferred each year and many of the temporarily deferred donors do not return to donate blood. This study analyzed actual deferral and return donation data from the American Red Cross to further assess the impact of donor deferral on donor availability. STUDY DESIGN AND METHODS: Voluntary blood donors who presented between 2001 and 2006 were included in this study. Deferred donors were classified into three groups according to their history of presentation during the prior 2 years: Group 1 with no prior donation or deferral, Group 2 with prior donation but no deferral, and Group 3 with prior deferral. Temporarily deferred donors in Groups 1 and 2 who did not return during the next 3 years were considered lost donors. All indefinitely deferred donors were lost donors. RESULTS: A mean of 12.8 percent of a total of 47,814,370 donor presentations between 2001 and 2006 resulted in a deferral. While majority of the deferrals were related to donor safety reasons, deferrals for recipient safety reasons accounted for 22.6 percent of deferrals or 2.9 percent of total presentations. Temporary and indefinite deferrals for recipient safety‐related reasons collectively caused an estimated loss of 647,828 donors during the 6 years. An additional 1,042,743 donors were lost due to deferrals for donor safety‐related reasons during the same period. CONCLUSIONS: The results on donor loss after deferral call attention to the impact of donor deferrals on donor availability and the need to monitor and assess the necessity and effectiveness of such deferrals.     

Deconstructing the risk for malaria in United States donors deferred for travel to Mexico

BACKGROUND: More than 66,000 blood donors are deferred annually in the United States due to travel to malaria‐endemic areas of Mexico. Mexico accounts for the largest share of malaria travel deferrals, yet it has extremely low risk for malaria transmission throughout most of its national territory, suggesting a suboptimal balance between blood safety and availability. This study sought to determine whether donor deferral requirements might be relaxed for parts of Mexico without compromising blood safety. STUDY DESIGN AND METHODS: Travel destination was recorded from a representative sample of presenting blood donors deferred for malaria travel from six blood centers during 2006. We imputed to these donors reporting Mexican travel a risk for acquiring malaria equivalent to Mexican residents in the destination location, adjusted for length of stay. We extrapolated these results to the overall US blood donor population. RESULTS: Risk for malaria in Mexico varies significantly across endemic areas and is greatest in areas infrequently visited by study donors. More than 70% of blood donor deferrals were triggered by travel to the state of Quintana Roo on the Yucatán Peninsula, an area of very low malaria transmission. Eliminating the travel deferral requirement for all areas except the state of Oaxaca might result in the recovery of almost 65,000 blood donors annually at risk of approximately one contaminated unit collected every 20 years. CONCLUSION: Deferral requirements should be relaxed for presenting donors who traveled to areas within Mexico that confer exceptionally small risks for malaria, such as Quintana Roo.     

Analysis of donor-deferral pattern in a voluntary blood donor population

SUMMARY. A reterospective analysis of records of the deferred donors from 1 October 1992 to 31 December 1993 was performed. Of 14,269 prospective blood donors (13,030 males and 1,239 females), 2,431 (16.4%) donors were disqualified for various reasons: 8-1% of the donors were deferred for non-pathological causes while 91-9% were deferred for medical reasons. The most common cause for non-pathological deferral was volunteers attending below the minimum acceptable age (5-2%). Abnormal findings on physical examination accounted for 57-2% of the deferrals in which low body weight was the most common finding (32-3%) followed by low Hb (18-6%). A past history of jaundice was the leading cause for deferral on medical interview.
Numerous prospective donors are currently being deferred based on empirically derived criteria. By developing strategies to identify and rationalize donor selection criteria, the blood transfusion services should be able to decrease unnecessary deferrals.     

The impact of temporary deferral due to low hemoglobin: future return,time to return,and frequency of subsequent donation

BACKGROUND: This study investigated the effects of a 6‐month deferral due to low hemoglobin (Hb) on the subsequent donation patterns of Australian whole blood donors. STUDY DESIGN AND METHODS: The study was a retrospective cohort study of the donation patterns of all whole blood donors deferred for low Hb during a 2‐month period compared with donors who were not deferred. Donations 3 years after eligibility to give blood were recorded. Analysis of proportion returning, time to return, and frequency of donation was performed using logistic regression, survival analysis, and negative binomial regression. RESULTS: Among first‐time donors, 20.9% of low Hb–deferred donors returned during the follow‐up period versus 69.9% of those not deferred. Among repeat donors, 64.0% of deferred donors returned versus 91.0% of those not deferred. Temporary deferral delayed time to first return (p < 0.001), reduced frequency of donation (2.4 donations per donor before deferral compared to 1.1 per donor in first year of follow‐up), and increased the likelihood of dropping out in later years of follow‐up. However, if a donor returned promptly once eligible and gave more donations in the first year, the negative impact on future donation patterns was diminished. High frequency of attendance before deferral was the strongest predictor of time to return and future donation frequency. CONCLUSION: Deferral for low Hb had a strong effect on first‐time and repeat donors. This study highlights the influence of strong donation habits on return after deferral and the importance of encouraging donors to return promptly once eligible.     

Predictive ability of sequential surveys in determining donor loss from increasingly stringent variant Creutzfeldt-Jakob disease deferral policies

BACKGROUND: Predonation screening questions about travel increase the safety of the blood supply from diseases such as variant Creutzfeldt-Jakob disease (vCJD) and malaria. This study examines the ability of sequential surveys to predict actual travel deferrals and the operational validity of travel questions. STUDY DESIGN AND METHODS: To assess donor travel histories before implementing key deferral policies, two donor surveys were carried out at Canadian Blood Services collection sites in February 1999 (8026 donors) and March 2001 (13,623 donors). In-person interviews were carried out with 1530 donors to assess the operational validity of the short travel question. Time-series analysis was used to determine whether there was a change in deferrals when deferral policies were implemented. Predicted donor loss estimates based on survey results were compared with actual deferrals. RESULTS: Deferrals increased significantly (p < 0.05) when vCJD deferral policies were implemented in October 1999 and September 2001, but not in October 2000. Survey data accurately predicted deferrals 6 months after implementation from the initial policy (2.51% predicted vs. 2.51% actual), but there were fewer deferrals than predicted for the second (2.89% predicted vs. 2.26% actual, p < 0.01) and third deferral policies (3.10% predicted vs. 1.89% actual, p < 0.01). There was 96 percent agreement between donor responses to a short screening question and a detailed travel history. CONCLUSION: The initial survey accurately predicted the actual donor deferral rate, but the deferral rate was less than predicted for subsequent, more stringent donor deferral policies. Donors answered a short travel question suitable for donor screening similarly to a very detailed travel history.     

Evaluation of blood donor deferral causes in the Trinidad and Tobago National Blood Transfusion Service

summary . The majority of blood donations in Trinidad and Tobago are made as replacement by family members or friends. National Blood Transfusion Policy was drafted in 2007 to promote voluntary, repeated donation. The objective of this study is to assess the current rate and reasons for donor deferral, and the aim is to guide the proposed donor education and recruitment programme. A retrospective study of pre-donation deferral of prospective blood donors at the National Blood Transfusion Centre, Port of Spain, Trinidad and Tobago, was conducted. Records of all pre-donation deferrals over a 12-month period were studied. As many as 11 346 pre-donation screening interviews were conducted. There were 4043 (35.6%) deferrals. The most common reasons for donor deferral were exposure to high-risk sexual activity (27.6%), low haemoglobin 22.2% and hypertension 17.5%. Other reasons such as medication, chronic medical illness, tattoos, travel history, recent pregnancy, surgery or presentation outside the accepted age limit caused 33.8% of all deferrals and the majority (34.7%) of male deferrals. Low haemoglobin (44.5%) was the most common reason among females. The rate of deferral of voluntary donors was not significantly different from that for replacement donors (31.7 vs. 35.4%, P = 0.25). This study exposed a lack of public awareness as the principal reason for an unacceptably high rate of donor deferral. Donor education about selection criteria needs to be urgently addressed as an objective of the National Policy. Monitoring and evaluation of deferral rates and reasons could be used as one indicator of the effectiveness of the Policy.     

Quantifying losses to the donated blood supply due to donor deferral and miscollection

BACKGROUND: Donors are deferred for multiple reasons. Losses related to disease marker rates are well established. Donor and donation losses for other reasons, however, have not been extensively quantified. STUDY DESIGN AND METHODS: To quantify these losses, three data sets from the Blood Centers of the Pacific were combined, permitting detailed analysis of year 2000 allogeneic whole-blood donations. RESULTS: During 2000, 13.6 percent of 116,165 persons who presented for donation were deferred at presentation. Short-term deferral accounted for 68.5 percent (hematocrit was most common at 60%); long-term deferral accounted for 21 percent (travel to a malarial area and tattoo or other nonintravenous drug use needle exposure were most common at 59 and 29%, respectively); and multiple-year or permanent deferral accounted for 10.5 percent (UK travel [variant Creutzfeldt-Jakob disease] risk and emigration from a malarial area were most common at 38 and 11%, respectively). Disease-marker-reactive donations represented 0.9 percent of donor outcomes. The prevalence of deferral and also miscollection (under- and overweight units) varied by age, sex, and first-time versus repeat donor status. Overall, miscollection led to a loss of 3.8 percent of 100,141 collections, ranging from 1.9 percent in repeat male donors 40 to 54 years of age to 10.7 percent in first-time female donors 16 to 24 years of age. CONCLUSION: Loss of units from both first-time and repeat donors due to temporary deferral and loss of units from miscollection are more common events than losses due to disease marker testing. Some of these losses may be avoidable and could increase the blood supply without having to recruit new donors.     

Donor return after temporary deferral

BACKGROUND: The consequences of temporary predonation deferral are unsatisfactorily understood. Studies have found that deferral negatively impacts future donor return. However, the applicability of these findings across centers has not been established. STUDY DESIGN AND METHODS: Using a cohort design, presenting donors with a temporary deferral in 2006 to 2008 in one of six categories (low hematocrit [Hct], blood pressure or pulse, feeling unwell, malaria travel, tattoos or piercing and related exposures, or could not wait or second thoughts) were passively followed for up to a 3‐year period for the time to first return after deferral expiration at six US blood centers. Time‐to‐event methods were used to assess return. We also analyzed which donor characteristics were associated with return using multivariable logistic regression. RESULTS: Of 3.9 million donor presentations, 505,623 resulted in deferral in the six categories. Low Hct was the most common deferral, had the shortest median time to return (time in days when 50% of deferred donors had returned), and had the largest cumulative proportion of donors returning. Deferrals of shorter duration had better return. Longer‐term deferrals (up to 1 year in length) had the lowest cumulative return proportion, which did not exceed 50%. Return was associated with previously identified factors such as repeat donor status, older age, and higher educational attainment regardless of the type of deferral. In addition, return was associated with having been born in the United States and donation at fixed sites. CONCLUSION: The category of temporary deferral influences the likelihood of future return, but the demographic and donation factors associated with return are largely consistent regardless of the deferral.     

Limited effectiveness of donor deferral registries for transfusion-transmitted disease markers

BACKGROUND: Donor deferral registries (DDRs) detect repeat donations by previously deferred donors and prevent their release. The utility of DDRs has not been objectively demonstrated. STUDY DESIGN AND METHODS: A total of 10.2 million first-time donors to the American Red Cross from 1995 through 2002 were reviewed to identify donors deferred by screening tests for human immunodeficiency virus (HIV; 0.19% of donors), hepatitis C virus (HCV; 0.55%), and hepatitis B virus (HBV; 0.13%). All repeat-reactive (RR) donors were deferred despite confirmatory testing. Donors were notified and counseled about their test results and deferral. Their subsequent donation behavior was assessed. RESULTS: A total of 414 HIV-deferred donors (2.1%), 471 HCV-deferred donors (0.8%, p < 0.001 vs. HIV and HBV), and 222 HBV-deferred donors (1.6%, p < 0.01 vs. HIV) returned to donate despite their deferred status. For all three tests, confirmed-positive donors were less likely to return. Of donors originally confirmed positive, only 7 returning donors were negative by screening (thus the repeat donation interdicted from distribution by the DDR): 0 HIV RR donors, 2 of 36,092 HCV RR donors, and 5 of 8,404 HBV RR donors. Review of the laboratory results for the HCV donors and one HBV donor was consistent with originally false-positive confirmation tests. The four other HBV confirmed-positive donors were anti-hepatitis B core antigen-positive on their subsequent donation, which was discarded despite the DDR. CONCLUSION: Of 10.2 million donors, the DDR did not prevent the release of any potentially dangerous blood component due to inappropriate return of donors deferred for HIV, HCV, and HBV tests. The effectiveness of DDRs should be evaluated for other deferrals.     

Development and validation of a prediction model for low hemoglobin deferral in a large cohort of whole blood donors

BACKGROUND: Each year, approximately 5% of the invited blood donors is eventually deferred from donation because of low hemoglobin (Hb) levels. Estimating the risk of Hb deferral in blood donors can be helpful in the management of the donation program. We developed and validated a prediction model for Hb deferral in whole blood donors, separately for men and women. STUDY DESIGN AND METHODS: Data from a Dutch prospective cohort of 220,946 whole blood donors were used to identify predictors for Hb deferral using multivariable logistic regression analyses. Validity of the prediction models was assessed with a cross‐validation. RESULTS: A total of 12,865 donors (5.8%) were deferred because of a low Hb level. The strongest predictors of Hb deferral were Hb level measured at the previous visit, age, seasonality, difference in Hb levels between the previous two visits, time since the previous visit, deferral at the previous visit, and the total number of whole blood donations in the past 2 years for both men and women. The prediction models had an area under the receiver operating characteristic curve of 0.89 for men and 0.84 for women. Cross‐validation showed similar results and good calibration. CONCLUSION: Using a limited number of easy‐to‐measure characteristics enables a good prediction of Hb deferral risk in whole blood donors. The prediction models may guide the decision which donors to invite for a next donation and for which donors the invitation should be postponed. Potentially, this could decrease the number of Hb deferrals in blood donors.     

Characteristics of post donation information donors and comparison with appropriately deferred donors

BACKGROUND: Post donation information (PDI) is the most frequently reported biological product deviation (BPD) related to donor suitability and the health history screening process. PDI occurs when a deferrable health history known by the donor is not disclosed, but is subsequently disclosed at a future donation. STUDY DESIGN AND METHODS: PDI and appropriately deferred (AD) donors were identified at six US blood centers from July 1, 2006, to June 30, 2007. PDI and AD donors were categorized according to travel, medical, blood disease or exposure, and high‐risk–sexual and high‐risk–nonsexual deferrals. Information was obtained from BPD reports and blood center records. Predictors of PDI were identified using an adjusted logistic regression model controlling for select characteristics. RESULTS: There were 2059 PDI and 36,512 AD donors. PDI donors were significantly more likely to be male, older, and more educated than AD donors. Medical and high‐risk–sexual PDI donors were more likely to have more than six intervening donations before disclosure of deferrable history. PDI donors with a deferral reason due to high‐risk behaviors (both sexual and nonsexual) were 2.3 and 2.6 times more likely to be PDI than the reference group (travel PDI donors). CONCLUSIONS: No previous studies have described the characteristics of PDI donors or examined how PDI donors are different from AD donors for the same deferral reasons. We found that PDIs are more likely in older, male donors with higher levels of education when compared to AD donors.     

Prevalence of selected viral infections among temporarily deferred donors who returned to donate blood: American Red Cross blood donor study

BACKGROUND: Health history questions are introduced into the predonation interview to identify blood donors believed to pose a higher risk of infectious diseases to recipients. This study assesses the current impact of some of those questions. STUDY DESIGN AND METHODS: Donor deferral and donation data were extracted from a research database of the American Red Cross. The prevalence of hepatitis B surface antigen or antibodies to human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus was obtained for different groups of donors who were temporarily deferred in 2000 through 2001 and later returned to donate blood in 2000 through 2003. The results were compared with either first-time or repeat donors in 2000 through 2003, while controlling for differences in sex, age, and year of donation. RESULTS: Of donors temporarily deferred in 2000 through 2001 who had had no donation or deferral during the previous 2 years, only 22.08 percent subsequently returned to donate blood in 2000 through 2003. Donations from returning donors who had been deferred for potential infectious disease risk did not show a higher prevalence for any of the viral markers when those with no donation or deferral during the previous two years were compared with first-time donations, and those with prior donation were compared with repeat donations. CONCLUSION: Blood donors temporarily deferred in 2000 through 2001 for potential risk of viral infection who later returned to donate blood did not appear to pose a higher risk compared to first-time or repeat donors. The effectiveness of some of the currently used deferral questions in reducing viral risks warrants further study.     

Analysis of blood donors’ characteristics and deferrals related to COVID-19 in Iran

BackgroundWith the outbreak of the coronavirus disease in 2019, called COVID-19, Iranian Blood Transfusion Organization (IBTO) implemented the new deferrals. This study analyzed the COVID-19 deferrals of blood volunteers and compared the demographics, deferrals, and the donor status during the COVID-19 outbreak in 2019.Study design and methodsData were collected from the integrated blood donor database between Feb-Apr 2019 and 2020. Deferral reasons of COVID-19 were categorized as: those who have symptoms or live with a symptomatic family member, have direct exposure with a confirmed case, have travelled from the outbreak affected areas, and have fully recovered from confirmed COVID-19. The z-test analysis was used, and 95 % confidence intervals were calculated to compare the sample proportions.ResultsThe blood donations dropped to 26.09 % in 2020. The percent change of first-time blood donors, female donors, and donors within the age group of 45?54 years old was significantly greater in 2020 than the same time frame in 2019 (p < 0.05). The results showed that 0.58 % of volunteers were deferred from blood donation to avoid transmission of SARS-CoV-2. The rate of COVID-19 deferrals in all types except travelling to affected areas has increased in the second 30-day of the study (p < 0.05).ConclusionThe blood shortage that occurred during the COVID-19 outbreak was not due to increased deferral for COVID-19, but it was mostly due to a decrease in the number of volunteers who referred to BTCs.     

Characteristics and causes of pre-donation deferrals at a Chinese blood center

ObjectivesThe purpose of this retrospective analysis was to understand the causes and characteristics of the pre-donation deferral, so as to enhance blood safety and improve donor satisfaction.BackgroundBlood transfusion is crucial in managing a variety of different medical and surgical needs. Its benefits are manifold but there are risks for the recipients. Thus some blood donors are deferred from donating when they do not meet certain criteria. An in-depth understanding of the underlying causes of donor deferral will not only improve donor selection but also ensure blood safety and avoid donor complaints.Materials and methodsThis single-center experience was carried out from 26th July 2018 to 25th July 2019 on all whole blood donors in Tianjin, China. Donors’ demographics and information were retrieved; comparisons between deferral data were summarized by the Chi-square test using Statistical Product and Service Solutions (SPSS) application version 22. The difference between groups were considered statistically significant when p < 0.05.ResultsA total of 190,846 participants were included; whereby 119,951 (62.85 %) of participants were first-time blood donors. The pre-donation deferral rate was 9.26 %, and deferral was more likely seen in first-time donors, male donors, and donors of age above 35 years (p < 0.05). Overall, raised alanine aminotransferase (ALT) contributed to 48.46 % of all temporary deferrals, followed by lipaemia (20.71 %). For female donors, low hemoglobin was the leading cause of temporary deferral. Positive hepatitis B surface antigen (Hepatitis B) and syphilis were the two common causes of permanent deferrals, with incidence at 11.65 % and 3.93 %, respectively.ConclusionPre-donation deferral remains a significant problem in China and accounted for 9.26 % of participants in this study. Raised ALT and lipaemia were common temporary deferrals, especially among first-time donors, males, and older donors. Appropriate interventions should be taken to address the blood quality, improve the donor retention strategies in order to secure an adequate and safe blood supply.     

An Analysis of Bone Donor Deferral Rates in Scotland – a 6-Year Study

Background

The Scottish National Blood Transfusion Service (SNBTS) is the main provider of tissues in Scotland. Tissue collection programmes were established in the mid-1990s, and the range of tissues collected has increased progressively over the years.

Mathods

Whilst the majority of tissues are obtained from cadaveric donations, bone is collected only from living donors who are usually patients undergoing primary hip replacement surgery (surgical donors). The bone is collected in an operating theatre, and, once stored, no further processing takes place prior to issue. Bone that fails for any reason (quality, microbiology or virological nonnegative result) is discarded.

Results

The deferral rate amongst live surgical bone donors in Scotland is around 65%, and it has been slowly and progressively rising from around 55% over the past few years. This needed investigated, particularly because comparisons with blood donors show that the deferral rate amongst bone donors is more than double that of first-time blood donors (29.7%). Our processes and systems are standardised, and our cohort of bone bank nurses have all been similarly trained and competency assessed. Moreover our data collection was done in a uniform fashion. It was therefore possible to conduct a 6-year audit on bone donor deferrals. It was found that a history of transfusion (16%), history of malignancy (18%) and bone quality (26%) were the main reasons for bone donor deferrals, accounting for 60% of all deferrals.

Conclusions

When these are taken into account, the residual deferral rates become very similar numerically to blood donors. It is important to note however that there are significant differences between the blood and bone donor cohorts. This study also highlighted some of deferral reasons. Particularly malignancy is a cause of significant numbers of deferrals, and the evidence of transmissibility of malignancy through bone donation is not strong. More robust risk assessments should be undertaken prior to implementing deferral conditions.Key Words: Living bone donors, Deferral rates, Tissue donation, Femoral head     

Temporary deferral and donor return

Deferral from donation is usually for conditions that make the donor only temporarily unable to give. Based on questionnaires given to 1247 donors with subsequent follow-up of their donation records for 6 months, permanent psychological effects of deferral are suggested. Only one of 36 deferred first-time donors (2.8%) compared with 27.3 percent of those who were not deferred returned for a second donation during the next 6 months. Among most first-time donors, temporary deferral may be interpreted psychologically as providing a permanent excuse for not donating.     

Demographic variations in blood donor deferrals in a major metropolitan area

BACKGROUND: Presenting blood donors are screened to ensure both their safety and that of the recipients of blood products. Donors with identified risks are deferred from donating blood either temporarily or permanently. Minorities are underrepresented as donors in the United States and this may in part be a result of increased donor deferral rates in minorities compared to white individuals. STUDY DESIGN AND METHODS: Data consisted of deferred and successful blood donor presentations to the American Red Cross Southern Region in the metropolitan Atlanta area in 2004 to 2008. Bivariate and multivariate analyses were conducted by race/ethnicity, age group, and sex. RESULTS: A total of 586,159 voluntary donor presentations occurred in 2004 to 2008, of which 79,214 (15.6%) resulted in deferral. In the age 16 to 69 years subset (98.3% of the presentations), deferred presentations were mostly women (78.2%). The most common reason for donor deferral was low hemoglobin (62.6%). The donor deferral rate varied by race/ethnicity, age, and sex: whites (11.1%), Hispanics (14.1%), and African Americans (17.9%); 16‐ to 19‐year‐olds (17.0%) and 50‐ to 59‐year‐olds (11.7%); and females (20.0%) and males (6.2%). Compared to whites and Hispanics, African American females had the highest deferral rate in each age group. CONCLUSIONS: Minorities are disproportionately impacted by blood donor deferrals. Methods to decrease blood donor deferral rates among African Americans are needed.