Demographic correlates of low hemoglobin deferral among prospective whole blood donors

Population-based screening for anemia using first-time blood donors

Anemia is an important public health concern. Data from population-based surveys such as the National Health and Nutrition Examination Survey (NHANES) are the gold standard, but are obtained infrequently and include only small samples from certain minority groups. We assessed whether readily available databases of blood donor hemoglobin values could be used as a surrogate for population hemoglobin values from NHANES. Blood donor venous and fingerstick hemoglobin values were compared to 10,254 NHANES 2005-2008 venous hemoglobin values using demographically stratified analyses and ANOVA. Fingerstick hemoglobins or hematocrits were converted to venous hemoglobin estimates using regression analysis. Venous hemoglobin values from 1,609 first time donors correlated extremely well with NHANES data across different ages, genders, and demographic groups. Cigarette smoking increased hemoglobin by 0.26-0.59 g/dL depending on the intensity. Converted fingerstick hemoglobin from 36,793 first time donors agreed well with NHANES hemoglobin (weighted mean hemoglobin of 15.53 g/dL for donors and 15.73 g/dL for NHANES) with similar variation in mean hemoglobin by age. However, compared to NHANES, the larger donor data set showed reduced differences in mean hemoglobin between Blacks and other races/ethnicities. Overall, first-time donor fingerstick hemoglobins approximate US population data and represent a readily available public health resource for ongoing anemia surveillance.

The impact of HFE mutations on haemoglobin and iron status in individuals experiencing repeated iron loss through blood donation*

Frequent blood donors become iron deficient. HFE mutations are present in over 30% of donors. A 24-month study of 888 first time/reactivated donors and 1537 frequent donors measured haemoglobin and iron status to assess how HFE mutations impact the development of iron deficiency erythropoiesis. Donors with two HFE mutations had increased baseline haemoglobin and iron stores as did those with one mutation, albeit to a lesser extent. Over multiple donations haemoglobin and iron status of donors with HFE mutations paralleled those lacking mutations. The prevalence of HFE mutations was not increased in higher intensity donors. Thus, in general, HFE mutations do not temper donation-induced changes in haemoglobin and iron status. However, in Black donors there was an increase of H63D carriers at baseline, from 3·7% in first time/reactivated donors to 15·8% in frequent donors, suggesting that the relative effects of HFE mutations on iron absorption may vary between racial/ethnic groups. In secondary analyses, venous haemoglobin decreased more slowly in donors with ferritin ≥12μg/l; and haemoglobin recovery time was shorter in donors with reticulocyte haemoglobin (CHr) ≥32·6pg, indicating that these biochemical measures are better indicators of a donor's response to phlebotomy than their HFE mutation status.

Iron deficiency in blood donors: the REDS-II Donor Iron Status Evaluation (RISE) study

BACKGROUND

Blood donors are at risk of iron deficiency. We evaluated the effects of blood donation intensity on iron and hemoglobin (Hb) in a prospective study.

STUDY DESIGN AND METHODS

Four cohorts of frequent and first-time or reactivated (FT/RA) blood donors (no donation in 2 years), female and male, totaling 2425, were characterized and followed as they donated blood frequently. At enrollment and the final visit, ferritin, soluble transferrin receptor (sTfR), and Hb were determined. Models to predict iron deficiency and Hb deferral were developed. Iron depletion was defined at two levels: iron deficiency erythropoiesis (IDE) [log(sTfR/ferritin) ≥ 2.07] and absent iron stores (AIS; ferritin < 12 ng/mL).

RESULTS

Among returning female FT and RA donors, 20 and 51% had AIS and IDE at their final visit, respectively; corresponding proportions for males were 8 and 20%. Among female frequent donors who returned, 27 and 62% had AIS and IDE, respectively, while corresponding proportions for males were 18 and 47%. Predictors of IDE and/or AIS included a higher frequency of blood donation in the past 2 years, a shorter interdonation interval, and being female and young; conversely, taking iron supplements reduced the risk of iron depletion. Predictors of Hb deferral included female sex, black race, and a shorter interdonation interval.

CONCLUSIONS

There is a high prevalence of iron depletion in frequent blood donors. Increasing the interdonation interval would reduce the prevalence of iron depletion and Hb deferral. Alternatively, replacement with iron supplements may allow frequent donation without the adverse outcome of iron depletion.

Red blood cell transfusion and outcomes in patients with acute lung injury, sepsis and shock

Introduction

In this study, we sought to determine the association between red blood cell (RBC) transfusion and outcomes in patients with acute lung injury (ALI), sepsis and shock.

Methods

We performed a secondary analysis of new-onset ALI patients enrolled in the Acute Respiratory Distress Syndrome Network Fluid and Catheter Treatment Trial (2000 to 2005) who had a documented ALI risk factor of sepsis or pneumonia and met shock criteria (mean arterial pressure (MAP) < 60 mmHg or vasopressor use) within 24 hours of randomization. Using multivariable logistic regression, we examined the association between RBC transfusion and 28-day mortality after adjustment for age, sex, race, randomization arm and Acute Physiology and Chronic Health Evaluation III score. Secondary end points included 90-day mortality and ventilator-free days (VFDs). Finally, we examined these end points among the subset of subjects meeting prespecified transfusion criteria defined by five simultaneous indicators: hemoglobin < 10.2 g/dL, central or mixed venous oxygen saturation < 70%, central venous pressure ≥ 8 mmHg, MAP ≥ 65 mmHg, and vasopressor use.

Results

We identified 285 subjects with ALI, sepsis, shock and transfusion data. Of these, 85 also met the above prespecified transfusion criteria. Fifty-three (19%) of the two hundred eighty-five subjects with shock and twenty (24%) of the subset meeting the transfusion criteria received RBC transfusion within twenty-four hours of randomization. We found no independent association between RBC transfusion and 28-day mortality (odds ratio = 1.49, 95% CI (95% confidence interval) = 0.77 to 2.90; P = 0.23) or VFDs (mean difference = -0.35, 95% CI = -4.03 to 3.32; P = 0.85). Likewise, 90-day mortality and VFDs did not differ by transfusion status. Among the subset of patients meeting the transfusion criteria, we found no independent association between transfusion and mortality or VFDs.

Conclusions

In patients with new-onset ALI, sepsis and shock, we found no independent association between RBC transfusion and mortality or VFDs. The physiological criteria did not identify patients more likely to be transfused or to benefit from transfusion.

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.

Blood center practice and education for blood donors with anemia

BACKGROUND

Anemia is an early indicator of many diseases, yet blood donors with low hematocrit (Hct) often receive inadequate information about its medical importance. We sought to understand the types of information that are and should be provided to these donors.

STUDY DESIGN AND METHODS

Two companion studies were performed. The first investigated blood center practices for care of donors with low Hct including deferral length, information provided, and cutoff values used when referring donors for medical attention. The second was a randomized prospective pilot study comparing behavior of deferred donors receiving an "older" pamphlet providing a list of iron-rich foods or a "newer" pamphlet providing descriptions of common causes of anemia and advice for seeking medical attention.

RESULTS

More than 70% of centers defer donors for 1 day. Only 6% defer donors for more than 2 weeks. Most centers provide written and/or verbal information about low Hct. Only 35% have a cutoff value defining significant anemia that requires additional medical attention. In the study of donors with low Hct, significant disease was identified within 3 months after deferral in 2 of 104 subjects: metastatic lung cancer and acute lymphocytic leukemia. Only donors receiving the newer pamphlet reported that it "definitely improved" their ability to speak with their doctor about anemia.

CONCLUSIONS

The diagnosis of anemia in blood donors may be an indicator of significant undiagnosed disease. There are wide variations in how centers care for and educate donors with anemia. Donors with anemia should be provided improved and consistent educational information.

Minority donation in the United States: challenges and needs

PURPOSE OF REVIEW

In the United States, blood donation rates of African-Americans are 25-50% of that of white individuals. As African-Americans make up an ever increasing and now substantial minority, and African-American recipients of blood transfusion, both specialized, such as sickle cell disease patients, and general hospitalized patients, have a better chance of receiving phenotype-matched or appropriate red blood cell units when there is a significant percentage of products in the inventory from African-American donors, it is important to understand the reason for the observed difference.

RECENT FINDINGS

Possible reasons for this discrepancy in donation rates include increased rates of donor deferral and ineligibility; increased barriers to donation, such as fear and distrust; and different marketing and education strategies. Thus, to increase the blood availability to African-American recipients, the reasons for these donation rate differences must be better understood and subsequently addressed through improved blood donor recruitment programs. The majority of African-American donor recruitment programs have focused on donating for sickle cell disease patients, particularly children, which have been of limited success.

SUMMARY

Significant improvements in African-American donor recruitment are needed to adequately meet the demand of African-American patients as well as the entire population.

Iron deficiency in blood donors: analysis of enrollment data from the REDS-II Donor Iron Status Evaluation (RISE) study

BACKGROUND

Regular blood donors are at risk of iron deficiency, but characteristics that predispose to this condition are poorly defined.

STUDY DESIGN AND METHODS

A total of 2425 red blood cell donors, either first-time (FT) or reactivated donors (no donations for 2 years) or frequent donors, were recruited for follow-up. At enrollment, ferritin, soluble transferrin receptor (sTfR), and hemoglobin were determined. Donor variables included demographics, smoking, dietary intake, use of iron supplements, and menstrual and/or pregnancy history. Models to predict two measures of iron deficiency were developed: Absent iron stores (AIS) were indicated by a ferritin level of less than 12 ng/mL and iron-deficient erythropoiesis (IDE) by a log(sTfR/ferritin) value of 2.07 or greater.

RESULTS

A total of 15.0% of donors had AIS and 41.7% IDE. In frequent donors, 16.4 and 48.7% of males had AIS and IDE, respectively, with corresponding proportions of 27.1 and 66.1% for females. Donation intensity was most closely associated with AIS and/or IDE (odds ratios from 5.3 to 52.2 for different donation intensity compared to FT donors). Being female, younger, and/or menstruating also increased the likelihood of having AIS and/or IDE, as did having a lower weight. Marginally significant variables for AIS and/or IDE were being a nonsmoker, previous pregnancy, and not taking iron supplements. Dietary variables were in general unrelated to AIS and/or IDE, as was race and/or ethnicity.

CONCLUSION

A large proportion of both female and male frequent blood donors have iron depletion. Donation intensity, sex and/or menstrual status, weight, and age are important independent predictors of AIS and/or IDE. Reducing the frequency of blood donation is likely to reduce the prevalence of iron deficiency among blood donors, as might implementing routine iron supplementation.