Epidemiology of donors and recipients: lessons from the SCANDAT database

Harnessing the potential of data-driven strategies to optimise transfusion practice

No one doubts the significant variation in the practice of transfusion medicine. Common examples are the variability in transfusion thresholds and the use of tranexamic acid for surgery with likely high blood loss despite evidence-based standards. There is a long history of applying different strategies to address this variation, including education, clinical guidelines, audit and feedback, but the effectiveness and cost-effectiveness of these initiatives remains unclear. Advances in computerised decision support systems and the application of novel electronic capabilities offer alternative approaches to improving transfusion practice. In England, the National Institute for Health and Care Research funded a Blood and Transplant Research Unit (BTRU) programme focussing on 'A data-enabled programme of research to improve transfusion practices'. The overarching aim of the BTRU is to accelerate the development of data-driven methods to optimise the use of blood and transfusion alternatives, and to integrate them within routine practice to improve patient outcomes. One particular area of focus is implementation science to address variation in practice.

HTLV-1 and blood donation

Human T-cell leukaemia virus type 1 (HTLV-1) is a human retrovirus that causes adult T-cell lymphoma and HTLV-associated myelopathy. In this issue, Rosadas et al. use data from a recent WHO report to describe how blood banks test for HTLV-1 and how this testing contributes to public health surveillance for the virus. Commentary on: Rosadas et al. HTLV-1 screening of blood donations: we are systematically missing opportunities. Br J Haematol 2023;202:1220-1223.

The Stockholm-Gotland perinatal cohort-A population-based cohort including longitudinal data throughout pregnancy and the postpartum period

BACKGROUND

Register-based reproductive and perinatal databases rarely contain detailed information from medical records or repeated measurements throughout pregnancy and delivery. This lack of enriched pregnancy and birth data led to the initiation of the Swedish Stockholm-Gotland Perinatal Cohort (SGPC).

OBJECTIVES

To describe the strengths of the SGPC, as well as the unique research questions that can be addressed using this cohort.

POPULATION

The SGPC is a prospectively collected, population-based cohort that includes all births (from 22 completed gestational weeks onwards) between 1 January 2008 and 15 June 2020 in the Stockholm and Gotland regions of Sweden (N 335,153 singleton and N 11,025 multiple pregnancies).

DESIGN

Descriptive study.

METHODS

The SGPC is based on the electronic medical records of women and their infants. The medical record system is used for all antenatal clinic visits and admissions, delivery and neonatal admissions, as well as postpartum clinical visits. SGPC has been further enriched with data linkages to 10 Swedish National Health Care and Quality Registers.

PRELIMINARY RESULTS

In contrast to other reproductive and perinatal databases available in Sweden, including the Medical Birth Register and the Pregnancy Register, SGPC contains highly detailed medical record data, including time-varying serial measurements for physiological parameters throughout pregnancy, delivery, and postpartum, for both mother and infant. These strengths have enabled studies that were previously inconceivable; the effects of serial measurements of pregnancy weight gain, changes in haemoglobin counts and blood pressure during pregnancy, fetal weight estimations by ultrasound, duration of stages and phases of labour, cervical dilatation and oxytocin use during delivery, and constructing reference curves for umbilical cord pH.

CONCLUSIONS

The SGPC-with its rich content, repeated measurements and linkages to numerous health care and quality registers-is a unique cohort that enables high-quality perinatal studies that would otherwise not be possible.

Red Blood Cell Donor Sex Associated Effects on Morbidity and Mortality in the Extremely Preterm Newborn

Transfusion exposure increases the risk of death in critically ill patients of all ages. This was thought to relate to co-morbidities in the transfusion recipient. However, donor characteristics are increasingly recognised as critical to transfusion recipient outcome with systematic reviews suggesting blood donor sex influences transfusion recipient health. Originally focusing on plasma and platelet transfusions, retrospective studies report greater risks of adverse outcomes such as transfusion related acute lung injury in those receiving products from female donors. There is increasing awareness that exposure to red blood cells (RBCs) poses a similar risk. Recent studies focusing on transfusion related outcomes in extremely preterm newborns report conflicting data on the association between blood donor sex and outcomes. Despite a renewed focus on lower versus higher transfusion thresholds in neonatal clinical practice, this group remain a heavily transfused population, receiving on average 3-5 RBC transfusions during their primary hospital admission. Therefore, evidence supporting a role for better donor selection could have a significant impact on clinical outcomes in this high-risk population. Here, we review the emerging evidence for an association between blood donor sex and clinical outcomes in extremely preterm newborns receiving one or more transfusions.

Patterns and determinants of blood transfusion in intensive care in Sweden between 2010 and 2018: A nationwide, retrospective cohort study

Background

Intensive care unit (ICU) patients are transfused with blood products for a number of reasons, from massive ongoing hemorrhage, to mild anemia following blood sampling, combined with bone marrow depression due to critical illness. There's a paucity of data on transfusions in ICUs and most studies are based on audits or surveys. The aim of this study was to provide a complete picture of ICU‐related transfusions in Sweden.

Methods

We conducted a register based retrospective cohort study with data on all adult patient admissions from 82 of 84 Swedish ICUs between 2010 and 2018, as recorded in the Swedish Intensive Care Register. Transfusions were obtained from the SCANDAT‐3 database. Descriptive statistics were computed, characterizing transfused and nontransfused patients. The distribution of blood use comparing different ICUs was investigated by computing the observed proportion of ICU stays with a transfusion, as well as the expected proportion.

Results

In 330,938 ICU episodes analyzed, at least one transfusion was administered for 106,062 (32%). For both red‐cell units and plasma, the fraction of patients who were transfused decreased during the study period from 31.3% in 2010 to 24.6% in 2018 for red‐cells, and from 16.6% in 2010 to 9.4% in 2018 for plasma. After adjusting for a range of factors, substantial variation in transfusion frequency remained, especially for plasma units.

Conclusion

Despite continuous decreases in utilization, transfusions remain common among Swedish ICU patients. There is considerable unexplained variation in transfusion rates. More research is needed to establish stronger critiera for when to transfuse ICU patients.

Lessons learned in the collection of convalescent plasma during the COVID-19 pandemic

Background

The lack of definitive treatment or preventative options for COVID‐19 led many clinicians early on to consider convalescent plasma (CCP) as potentially therapeutic. Regulators, blood centres and hospitals worldwide worked quickly to get CCP to the bedside. Although response was admirable, several areas have been identified to help improve future pandemic management.

Materials and methods

A multidisciplinary, multinational subgroup from the ISBT Working Group on COVID‐19 was tasked with drafting a manuscript that describes the lessons learned pertaining to procurement and administration of CCP, derived from a comprehensive questionnaire within the subgroup.

Results

While each country’s responses and preparedness for the pandemic varied, there were shared challenges, spanning supply chain disruptions, staffing, impact of social distancing on the collection of regular blood and CCP products, and the availability of screening and confirmatory SARS‐CoV‐2 testing for donors and patients. The lack of a general framework to organize data gathering across clinical trials and the desire to provide a potentially life‐saving therapeutic through compassionate use hampered the collection of much‐needed safety and outcome data worldwide. Communication across all stakeholders was identified as being central to reducing confusion.

Conclusion

The need for flexibility and adaptability remains paramount when dealing with a pandemic. As the world approaches the first anniversary of the COVID‐19 pandemic with rising rates worldwide and over 115 million cases and 2·55 million deaths, respectively, it is important to reflect on how to better prepare for future pandemics as we continue to combat the current one.

Research initiatives of blood services worldwide in response to the covid-19 pandemic

BACKGROUND AND OBJECTIVES

While coronavirus (COVID-19) is not transfusion-transmitted, the impact of the global pandemic on blood services worldwide is complex. Convalescent plasma may offer treatment, but efficacy and safety are not established. Measuring seroprevalence in donors would inform public health policy. Here, we survey blood services around the world to assess the different research programmes related to COVID-19 planned or in progress.

MATERIALS AND METHODS

Blood collection services were surveyed in June 2020 to determine whether they were participating in serosurveys or convalescent plasma collection and clinical trials.

RESULTS

A total of 48 countries (77% of those contacted) responded. Seroprevalence studies are planned or in progress in 73% of countries surveyed and in all continents, including low- and middle-income countries. Most aimed to inform public health policy. Convalescent plasma programmes have been initiated around the globe (79% of surveyed), about three quarters as clinical trials in high-, middle- and low-income countries.

CONCLUSION

Blood services around the world have drawn upon their operational capacity to provide much-needed seroprevalence data to inform public health. They have rapidly implemented preparation of potential treatment when few treatments are available and mostly as clinical trials. At the same time, they must continue to provide blood products for recipients despite challenges of working in a state of emergency. It is important to track and coordinate research efforts across jurisdictions to gain a composite evidence-based view that will influence future practice and preparative strategies.

Patterns of blood use in Sweden from 2008 to 2017: A nationwide cohort study

BACKGROUND

Transfusion patterns in Sweden have not been characterized on a nationwide level.

STUDY DESIGN AND METHODS

We conducted a nationwide descriptive cohort study in Sweden from 2008 to 2017. Data on blood donors, donations, component manufacture, transfusions, and transfused patients were extracted from Swedish portion of the Scandinavian Donations and Transfusions (SCANDAT3-S) database.

RESULTS

A total of 708 436 patients received 5 587 684 red cell, plasma, or platelet transfusions during the study period. The age-standardized transfusion rate decreased markedly during the study period for red cell units (from 53 to 39 units/1000 persons) and plasma units (from 11 to 4.9 units/1000 persons), but remained relatively constant for platelet concentrates. The transfusion rate was 30%-40% higher in males than in females in the first year of life, and higher in males over 45 years than in females. Between age 20 and 45, the majority of red cells were transfused to female patients with obstetric indications, whereas trauma was the predominant indication for male contemporaries. In females over 80 years, the largest proportion of red cells were administered due to trauma. Overall, hematological patients received 36% of all platelet units. There were large regional differences in transfusion rates for red cell units, ranging from less than 30 to greater than 60/1000 persons.

CONCLUSION

Transfusion rates in Sweden remain high but have decreased strikingly during the study period - with the exception of platelet transfusions. Based on the available data, it is difficult to draw firm conclusions about whether transfusion rates can be further reduced.

Association between recipient survival and blood donor age after blood transfusion in a surgery intensive care unit: a multicenter randomized controlled trial study protocol

BACKGROUND

Blood from younger individuals has been shown to improve physiological function in recipients in laboratory research, and many proteins from human peripheral blood show antisenescence capabilities. Thus, researchers have questioned whether blood from young donors is superior to blood from older donors. Blood transfusion is a key supportive therapy for trauma patients, and recent studies have reported the influence of blood donor age on recipient patient prognosis. Although some retrospective results found that blood from young donors improves survival, no influence of blood donor age was observed on outcomes in other study groups. The reasons for this discrepancy are complicated, but the fact that data were not obtained from randomized controlled trial (RCT) data should be considered. The current protocol and analysis method provide a feasible RCT design to evaluate the prognosis of severely ill surgery patients who were transfused with blood products from blood donors of different ages.

METHODS

The current study is a pragmatic multicenter RCT (open, parallel-group, non-masked, superiority trial). Recruited surgery intensive care unit patients will be randomized into three groups and transfused with blood products from male donors of different ages (< 25, 25-45, and > 45 years). Survival time will be measured within 28 days. The survival characteristics, possible interaction between variables, and potential factors associated with death will be analyzed by Kaplan-Meier analysis, two-way ANOVA, and Cox proportional hazards model, respectively.

TRIAL REGISTRATION

ChiCTR: ChiCTR190002. Registered on 22 March 2019. http://www.chictr.org.cn/showproj.aspx?proj=36867 .

Methodological considerations for linked blood donor-component-recipient analyses in transfusion medicine research

In recent years, there has been a concerted effort to improve our understanding of the quality and effectiveness of transfused blood components. The expanding use of large datasets built from electronic health records allows the investigation of potential benefits or adverse outcomes associated with transfusion therapy. Together with data collected on blood donors and components, these datasets permit an evaluation of associations between donor or blood component factors and transfusion recipient outcomes. Large linked donor-component recipient datasets provide the power to study exposures relevant to transfusion efficacy and safety, many of which would not otherwise be amenable to study for practical or sample size reasons. Analyses of these large blood banking-transfusion medicine datasets allow for characterization of the populations under study and provide an evidence base for future clinical studies. Knowledge generated from linked analyses have the potential to change the way donors are selected and how components are processed, stored and allocated. However, unrecognized confounding and biased statistical methods continue to be limitations in the study of transfusion exposures and patient outcomes. Results of observational studies of blood donor demographics, storage age, and transfusion practice have been conflicting. This review will summarize statistical and methodological challenges in the analysis of linked blood donor, component, and transfusion recipient outcomes.

Protect, repair, destroy or sacrifice: a role of oxidative stress biology in inter-donor variability of blood storage?

Red blood cells (RBCs) have been historically regarded as a critical model to investigate cellular and oxidant stress biology. First of all, they are constantly exposed to oxidant stress, as their main function is to transport and deliver oxygen to tissues. Second, they are devoid of de novo protein synthesis capacity, which prevents RBCs from replacing irreversibly oxidised proteins with newly synthesised ones. As such, RBCs have evolved to (i) protect themselves from oxidant stress, in order to prevent oxidant damage from reactive species; (ii) repair oxidatively damaged proteins, through mechanisms that involve glutathione and one-carbon metabolism; (iii) destroy irreversibly oxidised proteins through proteasomal or protease-dependent degradation; and (iv) sacrifice membrane portions through mechanism of vesiculation. In this brief review we will summarize these processes and their relevance to RBC redox biology (within the context of blood storage), with a focus on how polymorphisms in RBC antioxidant responses could contribute to explaining the heterogeneity in the progression and severity of the RBC storage lesion that can be observed across the healthy donor population.

2018 European Conference on Donor Health and Management

The third European Conference on Donor Health and Management (ECDHM) was held in Copenhagen from 5th to 7th September 2018 and was co-organised by the ECDHM committees and European Blood Alliance. This is an international conference with a focus on 'donor health', including donors of blood, organs and other substances of human origin, and remains the only conference focusing exclusively on donor medicine. This overview presents a selection of research topics in relation to iron, the keynote speeches and plenary talks. The keynote speeches cover the epidemiology of donors and recipients, whole-blood donor recruitment and retention and the safety of donors and recipients of plasma and plasma products. Talks from the plenary speakers reviewed modern multi-omic approaches to study red cell quality and the central, perennial question of what motivates a donor to give blood and how can this be encouraged.

Transfused trauma patients have better outcomes when transfused with blood components from young donors

The physiology of tissue healing and aging share common pathways. Both patient age and tissue healing are crucial factors predicting outcomes in trauma patients. The presented hypothesis focuses on the concept that transfused trauma patients have better outcomes when transfused with blood components from young donors. The age of the donor of a blood transfusion could affect recovery following a major traumatic insult and help avoid postinjury immune paralysis and its associated complications. The frequent transfusion of blood components to the severely injured trauma patient provides an opportunity for the recipient to benefit from the potentially favourable effect of blood originating from young donors. Different types of evidence support the presented hypothesis including work on soluble circulating factors, research on animal parabiontic models and epidemiological studies. Theories on the role of transfusion of cells, on bone marrow and on senolytics also represent grounds to elaborate pathways to test this hypothesis. The precise molecular mechanism underlying this hypothesis is uncertain. A beneficial effect on trauma patients following transfusion of blood could be due to a positive effect of blood donated from younger donors or instead to the lack of a negative effect possibly occurring when transfusing blood from older donors. Either way, identifying this mechanism would provide a powerful tool enhance long and short term recovery after trauma.

Donor incentives improve cardiovascular disease risk profile and donation rates

BACKGROUND

Blood centers may offer point-based reward systems or cardiovascular disease (CVD) screening to incentivize donors. However, combining these incentives to improve CVD risk and blood donation rates has not been studied.

STUDY DESIGN AND METHODS

Study was a three-arm prospective controlled trial: Group 1, control (routine points, no CVD screening); Group 2, CVD screening with routine points; and Group 3, CVD screening plus incentive double points. The primary objective was to determine if double versus routine incentive points led to improvement or maintenance of CVD risk profile assessed using self-reported changes in 1) reading food labels for calorie and fat content, 2) exercising daily, 3) reduced fat intake, and 4) increase in eating fruits and vegetables. Outcomes were compared at first and final (2-year) follow-up visits. As secondary outcome, median blood donation rates before enrollment and during study were compared.

RESULTS

A total of 570 donors (290 in Group 1, 134 in Group 2, 146 Group 3) were selected. At first follow-up visit, 71.4% in Group 3 versus 62.0% in Group 2 subjects reported at least one of four positive behavioral changes (p < 0.001). Increase in reading food labels for calorie and fat content was the most common change and higher in Group 3 (Group 3 from 60.9% to 79.1%; Group 2 from 67.6% to 77.5%; p < 0.001). Final evaluation showed significant increase in self-reported exercise in Group 3 only (from baseline 52.9% to 68.3%; p < 0.05). Group 3 reported higher increase in median number of donations/year during study enrollment (6.8 [IQR, 4.3-12] vs. baseline 4.6 [IQR, 3.2-7.1] donations/year) than Group 2 (5.6 [IQR, 4.2-10.5] vs. baseline 4.9 [IQR, 3.5-10.2]) and Group 1 (4.4 [IQR, 2.7-8.0] vs. baseline 4.4 [IQR, 2.5-6.0] donations/year; p < 0.001).

CONCLUSION

Positive donor reinforcement (double vs. routine points) resulted in better self-reported health maintenance behavior and increased donation rates.