Rising transfusion rates amidst stable blood supply: A Canadian perspective on emerging challenges for blood operators

Ensuring a consistent blood supply is essential for maintaining a robust healthcare system. National surveys over the past decade have shown a steady decline in blood utilization, which has been viewed positively as it offsets potential supply reductions due to an aging donor base.1-3 In contrast, recent data from Canadian Blood Services (CBS) and local hospitals indicate a countertrend, whereby transfusions per hospital admission have increased, particularly among certain patient populations.4, 5 These observations highlight the complexity of long-term forecasting and add important nuance to findings from national surveys, such as the American National Blood Collection and Utilization Survey (NBCUS), in the post-COVID era. Prior to and during the pandemic, a rise in transfusion rate per admission was balanced by a decline in the overall number of hospital admissions, resulting in a relatively stable blood demand. However, in the post-pandemic period both transfusion rates and admissions are increasing.4 If these trends continue, the combined effect of rising demand and an aging donor base could place significant strain on the blood supply.3, 4 Prior to the COVID-19 pandemic, the per capita utilization of red blood cell (RBC) issues was in decline.1, 2, 6, 7 Results from the NBCUS showed a decline in RBC transfusions from 2008 to 2017.2 Additionally, a study conducted by the National Heart Lung and Blood Institute (NHLBI) I Recipient Epidemiology and Donor Evaluation Study (REDS-III) reported a decrease from 14% to 10.8% in RBC usage between 2009 and 2012 in the United States.8 This was consistent with trends observed in Canada, with RBC issuance by CBS decreasing from 771,485 units in 2014/2015 to 689,791 units in 2020/2021 (see Figure 1).6 The decline in RBC demand was most likely driven by a multitude of factors, including restrictive transfusion strategies, new therapies to prevent and treat anemia, patient blood management (PBM) strategies, and advances in blood supply practices at the hospital level.9-11 A key strategy in PBM was the endorsement of conservative transfusion thresholds across major guidelines. This was partly driven by results from large randomized controlled trials across a variety of clinical contexts, such as acute myocardial infarction, gastrointestinal bleeding, orthopedic surgery, critical illness, and oncologic disorders.12-14 Other PBM strategies that have helped reduce RBC transfusions include improved anemia management and enhanced surgical blood conservation techniques, such as increased iron supplementation and intraoperative cell salvage.10, 11 In Canada, best practice guides from CBS and management toolkits, such as resources from the Ontario Regional Blood Coordinating Network (ORBCoN) have proven effective for optimizing blood inventory, notably in setting target stock levels and improving distribution efficiency.15-17 In the period leading up to the pandemic, transfusion rates had begun to plateau. The COVID-19 pandemic disrupted the stable blood supply, causing donor shortages, staffing challenges, and safety restrictions that led to a sharp decline in blood donations.18 Between February and May 2020, uncertainty led to widespread appointment cancellations, and CBS saw a 20% drop in donor attendance by March.19 Although blood demand also decreased, the unprecedented shift in donations led to several national blood shortages.20 Canada's National Plan for the Management of Shortages in Labile Blood Components (NBSP) provides a structured framework for responding to blood supply pressures through phased advisories; green, amber, and red, each guiding coordinated actions around inventory management, transfusion practices, and elective procedure review.21 At the tail-end of the pandemic, Canada entered a series of green phase advisories due to shortages of O+ RBCs from June to November 2023, prompting attention to the potential vulnerabilities in sustaining a stable blood supply.22 A detailed discussion of Canada's early pandemic blood shortages is provided in a previous commentary by Prokopchuk-Gauk et al.19 Rather than being isolated or incidental, these shortages likely reflect persistent challenges contributing to supply–demand mismatch and are creating a sustained pressure on the blood supply chain. In 2023, 11.6 million units of whole blood and RBCs were collected in the United States, and 11.3 million were transfused. This is a 4.1% decrease from 2021. In contrast, platelet transfusions rose by 2.1%, and pathogen-reduced platelet use jumped nearly 50%.23 Similarly, CBS data reported a rise in RBC issues, from 689,791 units in the 2020/2021 fiscal year to 734,724 units in 2023/2024.6 Several factors contribute to the growing transfusion demand. For example, improved cancer treatments including chemoimmunotherapies and cellular therapies have extended the lifespan of patients. These treatments can lead to subsequent deficits such as ongoing hyperproliferative anemias which often require long-term transfusion support.24-26 Limited access to primary care and an aging population are also leading to sicker patients at the time of admission.27 Similarly, advances in trauma care, cardiovascular interventions, immunotherapy, and cell therapies for relapsed cancers have extended survival across multiple transfusion-dependent patient populations.28-30 As surgical techniques improve, more patients, including those previously considered high risk, are now eligible for complex operations such as repeat surgeries for congenital heart defects.31, 32 Additionally, aging populations increasingly have access to bone marrow transplants, enabled by progress in stem cell research and supportive care protocols.33, 34 The demand for red cells may be expected to rise further following recent publications of studies in anemic patients with myocardial infarction and brain injury, arguing for more liberal transfusion strategies.30, 35-39 Collectively, these developments will contribute to a growing population of medically complex patients who survive longer and require ongoing transfusion support. In the face of growing demand, a decline in blood donors is emerging as a serious public health concern in Canada. A recent McKinsey report highlights that in the Pacific Northwest, donors aged 45 and older contribute 63% of the blood collected from repeat donors.3 However, as baby boomers age out of the donor pool, younger generations have not replaced their numbers.40 According to CBS data, the number of active donors has dropped to its lowest level in a decade, with a loss of ~31,000 active donors since the pandemic.41 Amid these demographic shifts in the donor base, Canada faces the prospect of reduced blood supply with frequent and prolonged blood shortages. To investigate trends in blood use, CBS requested data of red cell utilization from the GEMINI database. GEMINI is a large multi-center hospital data collaborative covering over 60% of inpatient hospitalizations in Ontario, Canada's largest province by population and transfusion use, with dedicated analyst support enabling targeted analyses of clinical practice.42 The resulting blood utilization report represented over 800,000 hospitalized patients across 25 hospitals in the province between December 2016 and May 2022.4, 5 The available data included patients from general medical wards, subspecialty medical wards, and critical care units. The analysis measured RBC use by calculating the average number of RBC units transfused per hospital admission each month, with subgroup analyses by patient age and clinical sub-populations to understand trends in RBC utilization. The analysis revealed an overall increase in the average RBC units transfused per admission from 0.32 in 2017 to 0.37 in 2022 (Figure 2). The increase was accentuated in patients admitted to subspecialty wards such as cardiology and oncology, and less evident in the critical care population.4 This aligns with contemporary trials in the ICU population supporting restrictive transfusion thresholds, potentially leading to more conservative blood use in critical care settings.24 Another key finding from the analysis was that the rise in transfusions per admission was observed across nearly all age groups (see Figure 3).4 In contrast, data from CBS's supply chain planning team showed a decline in overall RBC issuance during the same period, consistent with pre-pandemic trends observed in the United States.1, 2, 6 These findings suggest that although blood use per hospitalized patient was already increasing before the pandemic, the overall demand remained stable due to a lower number of admissions before and during the pandemic. In the post-pandemic period, however, both the number of medical admissions and the transfusion rate per admission have risen steadily across age groups, increasing demand for blood. The exception to this trend is seen in patients over 80 years old, where transfusion rates have remained stable, potentially reflecting a growing emphasis on palliative care in this population (see Figure 3).4, 42, 43 The observed concurrent increase in RBC demand from both admission volumes and transfusions per admission marks a shift in national blood use patterns. While conservative transfusion strategies may persist in certain populations, the data reflect broader systemic changes, including an aging donor base, rising patient complexity, and evolving care practices. Understanding specific drivers behind these trends will be essential to maintaining a responsive and sustainable blood supply. Although blood transfusion needs were declining prior to the COVID-19 pandemic, our analysis reveals a clear and sustained increase in both patient admissions and per-admission transfusion requirements in the post-pandemic period. This rise comes at a time when the donor base is shrinking due to an aging population and fewer new donors are stepping in to replace them. We believe the convergence of rising demand and a shrinking donor pool may represent a lasting shift rather than a temporary fluctuation, reflecting long-term changes in blood utilization. Without a stable and predictable blood supply, hospitals will face growing uncertainty in delivering lifesaving care, including oncologic treatments, surgeries, and emergency interventions. An Duong: Conceptualization; writing the original draft; and review and editing of the manuscript. Sheharyar Raza: Conceptualization; validation; review and editing of the manuscript. Marianne Waito: Validation; review and editing of the manuscript. Tanya Petraszko: Validation; review and editing of the manuscript and supervision. Asim Alam: Validation; review and editing of the manuscript and supervision. The authors have nothing to report. This study was supported by the Faculty of Medicine at the University of Ottawa, which provided a stipend for An Duong. The authors have disclosed no conflicts of interest. The authors have nothing to report. Data may be available upon request.