Psychological and behavioural impacts of the 2008 China earthquake on blood donors.

BACKGROUND AND OBJECTIVES: On May 12, 2008, a severe earthquake hit Sichuan province in China. A post-earthquake survey was conducted to study the earthquake's effect on blood donor behaviour and stress at three blood centres at varying distances from the epicentre. MATERIALS AND METHODS: A questionnaire was developed to assess donor post-traumatic stress disorders (PTSD) and attitudes toward giving blood. Responses were compared by centre and donor characteristics using multivariate logistic regression techniques. RESULTS: Of all 17 456 donors, the overall prevalence of PTSD was 13.2%. Donors who knew someone killed or injured by the earthquake were 2.1 times more likely to have PTSD than others (95% CI: 1.8-2.4). 85.2% of donors cited the earthquake as their reason for donating. 16.1% of donors felt it acceptable to be less honest about one's health history in an emergency. After adjusting for PTSD, geographic and demographic characteristics, the donors knowing someone killed or injured by the earthquake were 1.4 times (95% CI: 1.2-1.7) more likely to cite the earthquake as reason for donating, and 1.8 times (95% CI: 1.5-2.1) more likely to accept being less honest about one's health history in case of national emergency. CONCLUSIONS: The psychological and behavioural impacts of the earthquake on blood donors extended far from the epicentre. After a disaster, it is important to emphasize that donors must be truthful on the donor questionnaire as some donors appear willing to be less than honest when they perceive an increased need for blood products.

The African American church as a donation site: motivations and barriers.

BACKGROUND: In the United States, African Americans donate at approximately half the rate of whites and therefore are underrepresented in the volunteer blood donor pool. The goal of this study was to identify motivators and barriers to African Americans donating blood. STUDY DESIGN AND METHODS: A consortium of 15 predominantly African American churches of varying denominations in metropolitan Atlanta, Georgia, participated in an 81-item self-administered survey. The questionnaire was designed to assess participant's demographic background, blood donation frequency, motivators and barriers to donation, knowledge and beliefs regarding donation, and overall health status. RESULTS: A total of 930 participants completed the survey: 72% female, 55% age 40 or older, 99% African American, and 58% college-educated. The most frequent reported motivators were donating to help save a life (96%) and donating because blood is needed (95%), while the most frequent barriers were that they rarely think about it and they were afraid, nervous, or anxious to give blood (35%). The association of barriers with donation status, age, gender, and education level was stronger than for motivators. Fear was more common in nondonors than lapsed and current donors, youngest compared to older adults, and women than men and less in those with higher income. CONCLUSION: Motivators and barriers to blood donation in African American church attendees differ depending on the respondents' demographics. To increase the effectiveness of church drives, donor recruitment should focus on addressing these barriers and motivators.

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.

The relationship between meal frequency and body mass index in black and white adolescent girls: more is less.

OBJECTIVE: To document meal frequency and its relationship to body mass index (BMI) in a longitudinal sample of black and white girls from ages 9-19 years. DESIGN: Ten-year longitudinal observational study. SUBJECTS: At baseline, 1209 Black girls (539 age nine years, 670 age 10 years) and 1,166 White girls (616 age nine years, 550 age 10 years) were enrolled in the National Heart, Lung and Blood Institute Growth and Health Study (NGHS). MEASUREMENTS: Three-day food diaries, measured height and weight and self-reported physical activity and television viewing were obtained at annual in-person visits. RESULTS: Over the course of the study, the percentage of girls eating 3+ meals on all 3 days was reduced by over half (15 vs 6%). Participants who ate 3+ meals on more days had lower BMI-for-age z-scores. Black girls, but not white girls, who ate 3+ meals on more days were less likely to meet criteria for overweight. CONCLUSION: Meal frequency was related to BMI and should be considered when developing guidelines to prevent childhood overweight.

The RADAR repository: a resource for studies of infectious agents and their transmissibility by transfusion.

BACKGROUND: An ongoing issue in transfusion medicine is whether newly identified or emerging pathogens can be transmitted by transfusion. One method to study this question is through the use of a contemporary linked donor-recipient repository. STUDY DESIGN AND METHODS: The Retrovirus Epidemiology Donor Study Allogeneic Donor and Recipient (RADAR) repository was established between 2000 and 2003 by seven blood centers and eight collaborating hospitals. Specimens from consented donors were collected, components from their donations were routed to participating hospitals, and recipients of these units gave enrollment and follow-up specimens for long-term storage. The repository was designed to show that zero transmissions to enrolled recipients would indicate with 95 percent confidence that the transfusion transmission rate of an agent with prevalence of 0.05 to 1 percent was lower than 25 percent. RESULTS: The repository contains pre- and posttransfusion specimens from 3,575 cardiac, vascular, and orthopedic surgery patients, linked to 13,201 donation specimens. The mean number of RADAR donation exposures per recipient is 3.85. The distribution of components transfused is 77 percent red cells, 13 percent whole blood-derived platelet concentrates, and 10 percent fresh frozen plasma. A supplementary unlinked donation repository containing 99,906 specimens from 84,339 donors was also established and can be used to evaluate the prevalence of an agent and validate assay(s) performance before accessing the donor-recipient-linked repository. Recipient testing conducted during the establishment of RADAR revealed no transmissions of human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus. CONCLUSIONS: RADAR is a contemporary donor-recipient repository that can be accessed to study the transfusion transmissibility of emerging agents.

Does prevalence of transfusion-transmissible viral infection reflect corresponding incidence in United States blood donors?

BACKGROUND: Calculation of viral residual risk is dependent on estimating incidence, which is not easily obtainable by most blood centers. Prevalence, however, is readily available. Understanding whether prevalence reflects corresponding incidence may help blood centers monitor disease risks. STUDY DESIGN AND METHODS: With data on 12 million allogeneic donations, prevalence and incidence of transfusion-transmitted viral infections (TTVIs) were calculated. Relationships between prevalence (in total, first-time, and repeat donations) and incidence were analyzed for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) relative to temporal and donor demographic stratifications, respectively. RESULTS: Overall prevalence of HIV, HBV, and HCV did not consistently reflect corresponding incidence. The relationship between prevalence and incidence varied with time and donors' age and was virus-specific. CONCLUSION: Incidence of TTVIs cannot be easily predicted from overall prevalence. Accurate assessment of TTVI risk necessitates knowledge about donation histories and person-years at risk. Establishing comprehensive frameworks for monitoring blood donations and infectious disease markers remains a key to monitoring blood safety.

Detection of West Nile virus RNA and antibody in frozen plasma components from a voluntary market withdrawal during the 2002 peak epidemic.

BACKGROUND: The US West Nile virus (WNV) epidemic in the summer and fall of 2002 included the first documented cases of transfusion-transmitted WNV infection. In December 2002, the FDA supported a voluntary market withdrawal by the blood banking community of frozen blood components collected in WNV high-activity areas. At the time, the prevalence of viremia and serologic markers for WNV in the blood supply was undefined. STUDY DESIGN AND METHODS: In collaboration with America's Blood Centers, 1468 frozen plasma components (of approx. 60,000 frozen units voluntarily withdrawn from the market) were selectively retrieved from the peak epidemic regions and season (June 23, 2002-September 28, 2002). These units were unlinked, subaliquoted, and tested by WNV enzyme immunoassays (EIAs; Focus Technologies and Abbott Laboratories) and nucleic acid amplification tests (NATs; Gen-Probe Inc. and Roche Molecular Systems). RESULTS: Of the 1468 EIA results from Abbott and Focus, 7 were anti-immunoglobulin M (IgM)- and anti-immunoglobulin G (IgG)-reactive by both assays, 8 and 1 were IgM-only-reactive, and 8 and 23 were IgG-only-reactive, respectively. NAT by Gen-Probe and Roche Molecular Systems yielded one RNA-positive, antibody-negative unit containing approximately 440 RNA copies per mL. An additional 10-fold replicate NAT testing by Gen-Probe on 14 of 15 IgM-reactive specimens yielded 2 additional IgM- and IgG-reactive units with low-level viremia (i.e., 7/10 and 2/10 replicates tested reactive). CONCLUSION: The prevalence of acute (RNA-positive) and recent (IgM-seroreactive) WNV infections indicates that transfusion risk in high-risk areas could have been considerable and that voluntary market withdrawal of frozen components likely averted some WNV transfusion transmissions. The existence of very-low-level viremic units raises concerns, because WNV minipool NAT screening will miss such units and individual NAT may not completely correct this situation.

First year donation patterns predict long-term commitment for first-time donors.

BACKGROUND AND OBJECTIVES: Converting first-time donors to become regular donors continues to be a challenge facing blood centres. We examined whether first-time donors with frequent return in the first 12 months were more likely to become regular donors. SUBJECTS AND METHODS: The donation histories of 179 409 community whole-blood donors, whose first-time donation in 1991 was negative on donor screening tests, were evaluated. Donors were categorized by the number of donations made in the 12 months after (and including) their first donation. The donor return pattern in the subsequent 6 years, and its association with first-year donation frequency and demographics, was evaluated by using logistic regression analysis. A 'regular donor' was defined as one who returned to donate in at least 4 of the 6 years of follow-up. RESULTS: First-year donation frequency was significantly correlated with long-term donor return (P < 0.0001). Among those giving 1, 2, 3, 4 and > or = 5 donations in the first year, 4%, 11%, 21%, 32% and 42%, respectively, became regular donors (P < 0.0001). Similar associations between donation pattern and donor return behaviour were observed after adjusting for demographic variables (P < 0.0001). CONCLUSIONS: Strategies aimed at encouraging current donors to donate more frequently during the first year may help to establish a regular donation behaviour.

Comparison of demographic and donation profiles and transfusion-transmissible disease markers and risk rates in previously transfused and nontransfused blood donors.

BACKGROUND: Increasing concern about transfusion transmission of variant Creutzfeldt-Jakob disease has resulted in indefinite deferral of transfused donors in France and the UK. Little is known, however, about the impact of indefinite deferral of transfused donors on blood safety and availability in the US. STUDY DESIGN AND METHODS: Data were collected on allogeneic donations at five US blood centers during 1991 through 2000. Donation characteristics, prevalence, and incidence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) were compared between transfused and nontransfused donors. Unreported deferrable risk (UDR) and reasons to donate were evaluated with data from a mail survey. RESULTS: Transfusion history was reported by 4.2 percent of donors. Prevalence and incidence of HIV and HBV were comparable between transfused and nontransfused donors. Although HCV incidence was similar in both groups, HCV prevalence was nearly three times higher in transfused than in nontransfused first-time donors. UDR and reasons to donate were similar in the two groups, except transfused donors were less likely to donate for screening test results (odds ratio, 0.5; 95% confidence interval, 0.3-0.8). CONCLUSION: Transfused and nontransfused donors had similar viral incidence and comparable UDR, suggesting that indefinite deferral of transfused donors would unlikely improve blood safety. Until more is known about the prevalence and transfusion transmissibility of emerging agents, indefinite deferral of previously transfused donors in the US does not appear warranted.

Do blood donors read and understand screening educational materials?

BACKGROUND: Blood donors with high-risk behaviors may not self-defer because they failed to read or understand the screening educational materials. STUDY DESIGN AND METHODS: In 1993, a total of 34,726 allogeneic donors responded to an anonymous mail survey of 50,162 donors that inquired about demographics, donor status, amount of the donor educational materials read, new HIV knowledge gained, and donors' opinions on the length and difficulty of materials. RESULTS: Although 78 percent reported reading all materials, only 32 percent indicated reading carefully; 34 percent learned new information about HIV and 95 percent perceived the materials as easy to understand. First-time donors were more likely to read carefully (OR, 7.9) and gain more HIV knowledge from the materials (OR, 1.9) than repeat donors. Minority, less educated, screening test-reactive, and HIV test-seeking donors reported reading the materials more carefully and learning more about HIV than their respective counterparts. Donors with less education, those with reactive screening tests, those seeking HIV test results, and those not reporting a risk behavior were more likely to find the materials difficult to understand. CONCLUSION: Most donors reported skimming and not having difficulty understanding the educational materials. Some donors may be aware that they should not donate or are failing to assimilate the information in the materials. Methods to present information more clearly and concisely are clearly needed. However, some high-risk donors may still continue donating no matter how improved the educational materials are.

Prevalence of transfusion-transmissible viral infections in first-time US blood donors by donation site.

BACKGROUND: Understanding the donor base, infectious disease prevalence, and donation loss at various blood donation sites will help maximize blood collection efforts and blood availability. STUDY DESIGN AND METHODS: Using donation data collected at five US blood centers, the prevalence of HIV, HTLV, HBsAg, and HCV in first-time whole-blood donations at 10 donation sites was evaluated: military, education, religious, professional, industry, services, community, health care, government, and fixed sites. Donation loss from screening test reactivity at each donation site was also evaluated. RESULTS: During the study, 1.2 million first-time whole-blood donations were collected. Military and education sites had a low prevalence of all viral markers, except for HBsAg, which was highest at education sites. Variations in viral marker prevalence among donation sites were partially explained by donor demographic differences. Donation loss varied by donation site, ranging from 3.3 percent at education sites to 6.4 percent at industry sites, indicating differential efficiency of blood collection efforts. CONCLUSION: Different rates of positive viral test results and donation loss in first-time whole-blood donors were observed at various types of donation sites. This information may be useful in estimating the yield of usable units from specific blood drives and in allocating resources to meet blood center collection goals.

Knowledge of HIV/AIDS transmission and screening in United States blood donors.

BACKGROUND: Increased knowledge of HIV transmission and behavioral and test screening may encourage high-risk blood donors to self-defer. STUDY DESIGN AND METHODS: Knowledge of HIV transmission and screening and the association with demographics, screening test reactivity, and unreported deferrable risks (UDRs) was assessed by a 1998 anonymous mail survey sent to 92,581 blood donors, of whom 57 percent responded. Groups were compared by using weighted chi-square tests and logistic regression analysis. RESULTS: Four percent of the donors thought that it was very likely or somewhat likely for a person to contract HIV from donating blood, and 20 percent perceived a similar risk from blood transfusion. Only 60 percent of the donors knew that the available screening tests may not detect a recent infection. Thirty-seven percent either did not know or felt it was acceptable to donate blood to obtain HIV testing. Those most likely to answer knowledge questions incorrectly were more likely to have a higher prevalence of test reactivity or UDRs and to be

Prevalence, donation practices, and risk assessment of blood donors with hemochromatosis.

CONTEXT: Despite changes in eligibility policies, practical barriers limit blood donations from individuals with hemochromatosis. Increased knowledge of hemochromatosis donor characteristics may help foster further changes that will promote more donations. OBJECTIVES: To estimate the prevalence of donors diagnosed as having hemochromatosis and to compare rates of unreported deferrable risks for transfusion-transmissible viral infections (TTVIs), positive screening test results for TTVIs, and donation patterns between hemochromatosis patient donors and donors reporting no medical conditions necessitating phlebotomy (non-health-related donors). DESIGN: An anonymous mail survey conducted in 1998 as part of the ongoing Retrovirus Epidemiology Donor Study. SETTING AND PARTICIPANTS: Among a stratified probability sample of 92 581 blood donors from 8 geographically diverse US blood centers, 52 650 (57%) responded. MAIN OUTCOME MEASURES: Prevalence of hemochromatosis among blood donors; prevalence of unreported deferrable risks and positive screening test results for TTVIs among hemochromatosis patient donors vs non-health-related donors. RESULTS: One hundred ninety-seven respondents (0.4%) identified themselves as hemochromatosis patients and 50 079 (95.1%) as non-health-related donors. An estimated 0.8% of all donations were from hemochromatosis patients, 45.8% of whom reported that they had donated blood to treat their illness. The proportion of repeat donors was higher in hemochromatosis patients than in non-health-related donors (83.5% vs 76.5%; P =.03). Among repeat donors, 68.7% of hemochromatosis patients reported donating at least 3 times in the past year compared with 49.1% of non-health-related donors (P<.001). The prevalence of unreported deferrable risks for TTVIs was similar in hemochromatosis patients (2.0%) and non-health-related donors(3.1%) as was the overall prevalence of positive screening test results (1.3% of hemochromatosis patients vs 1.6% of non-health-related donors). CONCLUSIONS: Although significant numbers of hemochromatosis patients reported donating blood for therapeutic reasons, our findings suggest that this population does not present a greater risk to blood safety than other donors.

Incidence rates of viral infections among repeat donors:are frequent donors safer?

BACKGROUND: Incidence rates (IRs) for viral infections may vary with the frequency of donation among repeat, community, whole-blood (WB) donors, with IRs thought to be lower among donors with higher frequency of donation. STUDY DESIGN AND METHODS: IRs for HIV, HTLV, HCV, and HBV infection were stratified by frequency of donation among 868,403 repeat WB donors who gave approximately 4 million donations at five United States blood centers from 1991 through 96. All donors had given at least 2 donations during those years, with the first donation being nonreactive on confirmatory testing. Frequency of donation was measured in three ways: by the number of donations per year; at the time of donation, by the number of donations given within the preceding 2-year period; and by the number of donations given from 1991 through 1993. RESULTS: The IRs for HIV, HCV, and HBV infection did not appear to differ among donors with lower or higher numbers of donation per year. However, the IR for HTLV infection decreased as the number of donations per year increased (p = 0.0004). IRs for all viral markers remained stable, regardless of the number of donations given within the 2-year period before the donation. Although IRs for HIV, HTLV, and HCV infection did not vary by the number of donations given in 1991 through 1993, the IR for HBV infection appeared to be lower in donors who gave more donations in that period (p = 0.01). CONCLUSION: These findings do not provide evidence of a lower IR for transfusion-transmissible viral infections among repeat WB donors who give more frequently. Abbreviated screening histories for frequent repeat donors might not be advisable.

Repeat whole-blood and plateletpheresis donors:unreported deferrable risks, reactive screening tests, andresponse to incentive programs.

BACKGROUND: Evaluating plateletpheresis (PPH) and repeat community whole-blood (RWB) donors' responses to donation incentive programs is essential for developing effective donor retention programs. STUDY DESIGN AND METHODS: Using data from a 1998 anonymous questionnaire sent to 92,581 US blood donors, the prevalence of unreported deferrable risks, screening test reactivity, and response to incentives were compared in RWB and PPH donors by the use of weighted chi-square tests and logistic regression analyses. RESULTS: From 52,650 respondents, 38,884 RWB and 2,028 PPH donors were identified. Levels of screening test reactivity (1%) and unreported deferrable risks (UDRs, 2-3%) were similar in RWB and PPH donors. RWB and PPH donors were strongly encouraged or discouraged by similar incentives. Of the incentives that would encourage a higher proportion of UDR-free RWB donors to return, cholesterol screening and earning a blood credit appealed to >50 percent. Similar results were obtained for cholesterol screening in PPH donors. Community service or education credits, premarital screening, and cash had limited appeal for PPH and RWB donors, respectively, and would be more likely to differentially encourage donors with a UDR to return. CONCLUSION: Incentives that were associated with the greatest donor appeal and that minimized the potential recruitment of more risky donors were identified.

Racial differences in the sums of skinfolds and percentage of body fat estimated from impedance in black and white girls, 9 to 19 years of age: the National Heart, Lung, and Blood Institute Growth and Health Study.

OBJECTIVES: This National Heart, Lung, and Blood Institute Growth and Health Study report assesses racial differences in fat patterning in black and white girls ages 9 to 19 years, comparing the sum of triceps and subscapular skinfolds (SSFs) and percentage of body fat (%BF) from impedance as two indices of adiposity. It is hypothesized that racial differences in fat patterning manifest during puberty. RESEARCH METHODS AND PROCEDURES: SSF and %BF were measured annually. Racial differences in SSF and %BF were evaluated by age. Associations between %BF and SSF were evaluated using the Pearson's correlations coefficient. Classification agreement was evaluated using the kappa-statistic. Effects of pubertal stage and race on classification agreement were examined using multivariate models. RESULTS: White girls had a greater mean %BF at 9 to 12 years of age; black girls had a greater %BF thereafter. Black girls had a greater mean SSF at every age. The correlation coefficient between SSF and %BF was 0.79, and there was good agreement between %BF and SSF in separating high (>85th percentile) from not high (kappa = 0.60 for whites and 0.66 for blacks). SSF associated more with %BF in prepuberty and early puberty than in late puberty. DISCUSSION: Despite good correlations between %BF and SSF, the two methods indicate different fat patterns in black and white girls.

The potential impact of incentives on future blood donation behavior.

BACKGROUND: It is important to assess the potential efficacy and safety of offering donation incentives as part of recruitment and retention programs. STUDY DESIGN AND METHODS: In 1995, 7489 allogeneic donors responded to an anonymous mail survey that inquired about demographics, donation history, infectious disease risks, and the potential appeal of incentives. RESULTS: The projected net effect of offering blood credits and medical testing would be to motivate, respectively, 58 percent and 46 percent of donors to return, whereas offering an item of limited value would motivate 20 percent to do so. First-time and younger donors reported more frequently than repeat or older donors that incentives would appeal to them. Donors attracted by cash were 60 percent more likely to have a risk for transfusion-transmissible infections (p = 0.03). Although not statistically significant, the odds of being an at-risk donor were higher among individuals attracted by tickets to events (OR 1.5) and extra time off work (OR 1.2). CONCLUSION: These findings suggest that offering blood credits and (though to a lesser extent) items of limited value could be safe and effective strategies for retaining donors. Although medical tests were found to have broad appeal, studies are needed to identify tests in which donors would be most interested.

Racial divergence in adiposity during adolescence: The NHLBI Growth and Health Study.

BACKGROUND: Black women are particularly vulnerable to obesity, with a prevalence rate of >50%. The higher mortality and morbidity from cardiovascular disease, stroke, and diabetes have been attributed, in part, to their obesity. In recent years, a particular public health concern is the increasing secular trend in obesity with an even greater racial disparity, especially in girls and women. Between the early 1960s and late 1980s, the prevalence of obesity tripled in young black girls 6 to 11 years of age, while it doubled in white girls. Similarly, both overweight and obesity in adolescent girls 12 to 17 years of age also increased, with a greater increase again seen in adolescent black girls. This secular trend in obesity with a greater increase in black girls signals a potentially grave future chronic disease burden on black women, which is already higher than in white women. The increasing occurrence in children and adolescents of noninsulin-dependent diabetes, traditionally viewed as an adult-onset condition, may be a consequence of the currently high prevalence of obesity in American youth. Not surprisingly, this condition is seen more frequently among black youths. Prepubescent black girls are generally leaner than age-comparable white girls, but by 20 years of age, black women are considerably heavier than are white women. Thus, it is assumed that the racial disparity in adiposity evolves during adolescence. However, the specific age at which this occurs and underlying factors are yet to be identified because of the current paucity of longitudinal cohort data. OBJECTIVES: In 1985, the National Heart, Lung, and Blood Institute (NHLBI) initiated a 10-year longitudinal multicenter study (the NHLBI Growth and Health Study [NGHS]) to investigate the development of obesity in black and white girls during adolescence and its environmental, psychosocial, and cardiovascular disease risk factor correlates. The purpose of this report is to examine the natural history of adiposity and weight accretion during adolescence in a biracial cohort of girls to investigate the evolution of the racial divergence in adiposity and to examine the relationships between increases in adiposity and pubertal maturation, energy intake, and physical activity. PARTICIPANTS AND SETTING: A total of 2379 black (51%) and white (49%) girls, 9 to 10 years of age, were recruited from public and parochial schools in Richmond, California, and Cincinnati, Ohio, and from families enrolled in a large health maintenance organization in the Washington, DC area. Participant eligibility was limited to girls and their parents who declared themselves as being either black or white and who lived in racially concordant households. DESIGN AND STATISTICAL ANALYSIS: The NGHS is a multicenter prospective study of black and white girls with annual visits from 9 to 10 years of age through 18 to 19 years of age. The follow-up rate was 89% at the 10th annual visit. Skinfold measurements were obtained at the triceps, suprailiac, and subscapular sites with Holtain calipers. Sexual maturation was assessed by trained registered nurses. The onset of menarche was ascertained annually by questionnaire. All clinical assessments were conducted using a common protocol by centrally trained staff. Longitudinal regression (generalized estimating equations) models were used to examine the relationship between adiposity and race, age, pubertal maturation, daily energy intake, and physical activity. MAIN OUTCOME MEASURES: The main outcome measure was the sum of skinfolds (SSF) at the triceps, subscapular, and suprailiac sites as an index of adiposity for comparison between the 2 racial groups. Body mass index (BMI; weight in kilograms divided by height in meters, squared) distributions were examined by age and race. RESULTS: Racial differences in SSF, unadjusted for maturation, were evident at 10 years of age. For each chronological age, there was a higher proportion of black girls with more advanced pubertal maturation than white girls. The 15th percentiles for SSF were similar and remained thus throughout the study. The median for SSF for black girls, although similar to the median SSF of white girls at 9 years of age, became greater for black girls at 12 years of age (36 mm vs 32.5 mm) and at age 19 years the difference was 6 mm (49.5 mm vs 43.5 mm). In contrast, the difference in the 85th as well as the 95th percentile values for SSF were substantially higher in black girls at all ages (9 mm and 10 mm, or 18% and 15%, respectively, at age 9 years) and these racial differences widened with age (20 mm and 26 mm, or 25% and 24%, respectively, by age 19 years). The racial difference in the median BMI increased from 0.4 to 2.3 kg/m(2) between ages 9 and 19 years. Unlike SSF at the 15th percentile, the BMI for lean 9-year-old black girls was ~3% higher than whites. (ABSTRACT TRUNCATED)