Ferritin measurement IN Donors-Effectiveness of iron Monitoring to diminish iron deficiency and low haemoglobin in whole blood donors (FIND'EM): study protocol for a stepped wedge cluster randomised trial

Iron supplementation: A qualitative study on the perception of blood donors, blood collection staff and donor physicians

BACKGROUND AND OBJECTIVES

Iron supplementation is an effective strategy to mitigate donation-induced iron deficiency in blood donors. However, evidence on the perception of individuals involved in blood donation on iron supplementation as a blood service policy is lacking. This study aimed to evaluate the knowledge and perception of whole blood donors (donors), blood collection staff (collection staff) and donor physicians (physicians) regarding donation-induced iron loss and iron supplementation.

MATERIALS AND METHODS

Online focus group discussions had four to six participants and followed a structured questioning approach. All participants had to be fluent in Dutch to participate, and donors had donated at least five times. Sixteen donors, eight collection staff members and four physicians participated in this study. Recordings were transcribed, coded and analysed using a grounded theory approach.

RESULTS

Awareness of donation-induced iron loss was limited in donors. Donors and physicians were predominantly positive towards iron supplementation; the primary motivator for donors was to prevent deferral and reduce iron-deficiency-related symptoms. Improving donor health was the main argument for physicians to advocate iron supplementation. Staff had a critical view on iron supplementation as a policy, as they perceived it as unethical and possibly ineffective. A knowledge gap might underlie their concerns.

CONCLUSION

Most individuals involved in blood donation are positive towards iron supplementation as a blood service policy. If implemented, guidance and monitoring is desired and adequate education of all stakeholders is required.

Explainable haemoglobin deferral predictions using machine learning models: Interpretation and consequences for the blood supply

BACKGROUND AND OBJECTIVES

Accurate predictions of haemoglobin (Hb) deferral for whole-blood donors could aid blood banks in reducing deferral rates and increasing efficiency and donor motivation. Complex models are needed to make accurate predictions, but predictions must also be explainable. Before the implementation of a prediction model, its impact on the blood supply should be estimated to avoid shortages.

MATERIALS AND METHODS

Donation visits between October 2017 and December 2021 were selected from Sanquin's database system. The following variables were available for each visit: donor sex, age, donation start time, month, number of donations in the last 24 months, most recent ferritin level, days since last ferritin measurement, Hb at nth previous visit (n between 1 and 5), days since the nth previous visit. Outcome Hb deferral has two classes: deferred and not deferred. Support vector machines were used as prediction models, and SHapley Additive exPlanations values were used to quantify the contribution of each variable to the model predictions. Performance was assessed using precision and recall. The potential impact on blood supply was estimated by predicting deferral at earlier or later donation dates.

RESULTS

We present a model that predicts Hb deferral in an explainable way. If used in practice, 64% of non-deferred donors would be invited on or before their original donation date, while 80% of deferred donors would be invited later.

CONCLUSION

By using this model to invite donors, the number of blood bank visits would increase by 15%, while deferral rates would decrease by 60% (currently 3% for women and 1% for men).

A computational model for prediction of ferritin and haemoglobin levels in blood donors

Blood donors are at risk of iron deficiency anaemia. While this risk is decreased through ferritin-based deferral, ideally ferritin monitoring should also aid in optimising donation frequencies. We extended an existing model of haemoglobin (Hb) synthesis with iron homeostasis and validated the model on a cohort of 300 new donors whose ferritin levels were measured from stored blood samples collected over a 2-year period. We then used the donor's gender, body weight, height, and baseline Hb and ferritin levels to predict subsequent Hb and ferritin levels. The prediction error was within measurement variability in 88% of Hb level predictions and 64% of ferritin level predictions. A sensitivity analysis of the model revealed that baseline ferritin level was the most important in predicting future ferritin levels. Finally, we used the model to calculate the annual donation frequency at which donors would keep their ferritin level >15 ng/ml when measured after donating for 2 years. The mean annual donation frequency would then be 1.9 for women and 4.1 for men. The computational model, requiring baseline values only, can predict future Hb and ferritin levels remarkably well. This enables determination of optimal donation frequencies for individual donors at the start of their donation career.

The influence of blood donation before pregnancy on neonatal birth weight

Objective

To evaluate the effect of blood donation before pregnancy on neonatal birth weight.

Methods

A total of 14996 women with singleton pregnancies at full-term in Ningbo Medical Center Lihuili Hospital and Ningbo Women’s and Children’s Hospital from November 2019 to November 2020 were enrolled in this study. Detailed records of whole blood donation before pregnancy were obtained through Alipay software. The records were classified into three groups: nondonors, low-frequency donors and high-frequency donors according to the total numbers of blood donations in the 3-year period before pregnancy. The demographics and clinical information of the enrolled participants and their fetuses were collected from electronic medical records (EMRs). The effect of blood donations in the 3-year period before pregnancy on neonatal birth weight was analyzed.

Results

There was no significant difference in neonatal birth weight among the three groups (P = 0.373). In line with this, there was no association between the number of blood donations in the 3-year period before pregnancy and neonatal birth weight (β = 14.5; 95% confidence interval [CI]: -3.9, 31.4; P = 0.094) in the bootstrapped multivariate linear regression analysis models, adjusted for maternal age, number of pregnancies, number of deliveries, gestational age, mode of delivery, years of education and blood type in pregnant women. Compared to the nondonors, the risk of fetal macrosomia was higher in both low-frequency donors and all donors (OR: 1.539, 95% CI: 1.058, 2.134, P = 0.016; OR: 1.454, 95% CI: 1.033, 1.952, P = 0.021, respectively), in the bootstrapped binary logistic regression analysis models after adjusting for the variables mentioned above.

Conclusion

Our study showed that maternal blood donation in the 3-year period before pregnancy may not lead to a reduction in neonatal birth weight, but may be associated with the incidence of fetal macrosomia.

Ferritin Trajectories over Repeated Whole Blood Donations: Results from the FIND+ Study

Background: Depending on post-donation erythropoiesis, available iron stores, and iron absorption rates, optimal donation intervals may differ between donors. This project aims to define subpopulations of donors with different ferritin trajectories over repeated donations. Methods: Ferritin levels of 300 new whole blood donors were measured from stored (lookback) samples from each donation over two years in an observational cohort study. Latent classes of ferritin level trajectories were investigated separately using growth mixture models for male and female donors. General linear mixed models assessed associations of ferritin levels with subsequent iron deficiency and/or low hemoglobin. Results: Two groups of donors were identified using group-based trajectory modeling in both genders. Ferritin levels showed rather linear reductions among 42.9% of male donors and 87.7% of female donors. For the remaining groups of donors, steeper declines in ferritin levels were observed. Ferritin levels at baseline and the end of follow-up varied greatly between groups. Conclusions: Repeated ferritin measurements show depleting iron stores in all-new whole blood donors, the level at which mainly depends on baseline ferritin levels. Tailored, less intensive donation strategies might help to prevent low iron in donors, and could be supported with ferritin monitoring and/or iron supplementation.

Donation-induced iron depletion is significantly associated with low hemoglobin at subsequent donations

BACKGROUND

Blood donation is associated with a loss of hemoglobin (Hb)-bound iron. Hb levels recover relatively fast by using stored iron. However, it takes more time to replenish iron stores, potentially resulting in iron deficiency.

STUDY DESIGN

Hb and ferritin levels were measured in 5056 new, first-time, and repeat whole blood donors. We investigated whether increasing numbers of donations are associated with lower ferritin levels. Furthermore, we tested whether low ferritin levels are associated with low-Hb deferral at the subsequent donation attempt by performing logistic regression adjusted for age and stratified by sex.

RESULTS

Whereas mean Hb levels are relatively stable, ferritin levels significantly decrease with increasing numbers of donations and were approximately 50% lower for donors with >50 donations compared with those with 2-10 donations. Despite the poor correlation of ferritin and Hb levels, cross-sectional, iron-deficient donors (ferritin <15 ng/ml) had 21.8 (8.5-55.6) higher odds in men, 10.1 (6.1-16.5) in premenopausal women, and 11.7 (5.2-26.4) in postmenopausal women for Hb deferral at a subsequent visit.

DISCUSSION

To conclude, repeated donations may induce iron deficiency, which corresponds with an over tenfold increased risk of having insufficiently restored Hb levels at a subsequent donation attempt. Longer donation intervals and/or higher dietary or supplemental iron intake are warranted to prevent accumulated iron depletion and subsequent low-Hb deferral in whole blood donors.

Whole blood donors' post-donation symptoms diminish quickly but are discouraging: Results from 6-day symptom diaries

BACKGROUND

Whole blood donors may experience post-donation symptoms such as fatigue, dizziness, or headache after blood donation, which could influence donor retention. We aimed to examine post-donation symptoms during 1 week after whole blood donation, investigate donor characteristics associated with symptoms, and evaluate associations between symptoms and donor return.

METHODS

During 1 week, whole blood donors who donated successfully at one of the collection centers in The Netherlands were invited to participate. Three thousand seventy six donors filled in a diary, assessing post-donation symptoms during days 1 to 6 after donation. We used linear mixed models analyses to determine the change in post-donation symptoms after donation for male and female donors separately. Furthermore, we investigated associations between post-donation symptoms and donors' physical characteristics using multivariable regression and determined associations between symptoms and donor return.

RESULTS

Donors reported fatigue as the most common symptom, with approximately 3% of donors experiencing severe problems at the first day after donation. Multiple symptoms improved significantly up to day 3 after whole blood donation. Age, BMI, blood pressure (male donors), and blood volume (female donors) were significantly associated with post-donation symptoms. Donors with less fatigue after whole blood donation were more likely to return for their next donation within 31 days after receiving an invitation.

CONCLUSION

Post-symptoms improve up to 3 days after whole blood donation. Our results may help blood collection centers to identify donors more prone to post-donation symptoms and provide personalized information about the presence and course of post-donation symptoms, possibly increasing donor return rates.

Whole blood donor behavior and availability after deferral: Consequences of a new ferritin monitoring policy

Background

To prevent (negative consequences of) temporary deferral due to low hemoglobin, the Dutch national blood service Sanquin introduced a ferritin monitoring policy in 2017. Ferritin is measured after the donation (as opposed to before donation for hemoglobin), and low ferritin levels lead to deferral of 6 (ferritin 15‐30 ng/mL) or 12 months (ferritin <15 ng/mL). We explored the consequences of this policy on donor behavior and availability.

Study Design and Methods

We included all Dutch whole blood donors who made a donation (attempt) between 13 November and 31 December 2017. At that point, the ferritin monitoring policy was randomly implemented in 8 of 29 regional clusters of collection centers. We extracted information from Sanquin's donor database about donors' deferrals, subsequent donation attempts, and donation cessation (up to 31 December 2019). Donors deferred for low ferritin were compared to those deferred for low hemoglobin or other reasons, as well as to donors who were not deferred.

Results

A total of 55 644 donors were included (11% deferred). For donor behavior, we found that donors deferred for low ferritin less often unsubscribed and switched to other donation types, yet also made fewer donations in the follow‐up period. For availability, we found they were less often deferred, yet they were unavailable to donate for a longer period.

Conclusion

Results suggest that the implementation of a ferritin monitoring policy may lead to a decrease in donor availability and reduced donations. However, the policy is successful in retaining more donors and reducing low hemoglobin deferrals.

Comparison of four methods to measure haemoglobin concentrations in whole blood donors (COMPARE): A diagnostic accuracy study

OBJECTIVE

To compare four haemoglobin measurement methods in whole blood donors.

BACKGROUND

To safeguard donors, blood services measure haemoglobin concentration in advance of each donation. NHS Blood and Transplant's (NHSBT) customary method have been capillary gravimetry (copper sulphate), followed by venous spectrophotometry (HemoCue) for donors failing gravimetry. However, NHSBT's customary method results in 10% of donors being inappropriately bled (ie, with haemoglobin values below the regulatory threshold).

METHODS

We compared the following four methods in 21 840 blood donors (aged ≥18 years) recruited from 10 NHSBT centres in England, with the Sysmex XN-2000 haematology analyser, the reference standard: (1) NHSBT's customary method; (2) "post donation" approach, that is, estimating current haemoglobin concentration from that measured by a haematology analyser at a donor's most recent prior donation; (3) "portable haemoglobinometry" (using capillary HemoCue); (4) non-invasive spectrometry (using MBR Haemospect or Orsense NMB200). We assessed sensitivity; specificity; proportion who would have been inappropriately bled, or rejected from donation ("deferred") incorrectly; and test preference.

RESULTS

Compared with the reference standard, the methods ranged in test sensitivity from 17.0% (MBR Haemospect) to 79.0% (portable haemoglobinometry) in men, and from 19.0% (MBR Haemospect) to 82.8% (portable haemoglobinometry) in women. For specificity, the methods ranged from 87.2% (MBR Haemospect) to 99.9% (NHSBT's customary method) in men, and from 74.1% (Orsense NMB200) to 99.8% (NHSBT's customary method) in women. The proportion of donors who would have been inappropriately bled ranged from 2.2% in men for portable haemoglobinometry to 18.9% in women for MBR Haemospect. The proportion of donors who would have been deferred incorrectly with haemoglobin concentration above the minimum threshold ranged from 0.1% in men for NHSBT's customary method to 20.3% in women for OrSense. Most donors preferred non-invasive spectrometry.

CONCLUSION

In the largest study reporting head-to-head comparisons of four methods to measure haemoglobin prior to blood donation, our results support replacement of NHSBT's customary method with portable haemoglobinometry.