Risk-based decision-making for blood safety: preliminary report of a consensus conference

Risk-based Decision Making Definition: A Scoping Review of Food, Agricultural, Environmental, and Medical Literature

Risk-based decision making (RBDM) is a term that is used frequently as an aspirational goal in many fields, including health, engineering, environmental science, regulatory and, more recently, food safety. When RBDM is used in the literature, many different types of criteria are used to characterize a decision process as being "risk-based." Like the parable about the blind men and the elephant, everyone is confident they know what RBDM means even though there is no universal definition. The use of RBDM is gaining wide acceptance and implies a level of rigor and focus that many decisionmakers and stakeholders are interested in adopting. However, without one clear definition, there are questions about what a RBDM approach really means. This study summarizes peer-reviewed and gray literature that uses the term "RBDM" from the last 50 years in the agricultural, environmental, and medical areas. The criteria discussed were identified and organized into themes. A foundational definition is proposed to represent the most fundamental use of RBDM in the literature, and three themes covering the additional concepts presented in some of the literature were identified and added as themes within the definition. Results from this research will inform practitioners interested in following the principles of RBDM, and will help guide researchers who are interested in advancing this approach. The most immediate use will be to guide the development of a roadmap for a risk-based food safety system for low- and middle-income countries and to aid the global food safety community in moving toward RBDM.

Optimal portfolios of blood safety interventions: test, defer or modify?

A safe supply of blood for transfusion is a critical component of the healthcare system in all countries. Most health systems manage the risk of transfusion-transmissible infections (TTIs) through a portfolio of blood safety interventions. These portfolios must be updated periodically to reflect shifting epidemiological conditions, emerging infectious diseases, and new technologies. However, the number of available blood safety portfolios grows exponentially with the number of available interventions, making it impossible for policymakers to evaluate all feasible portfolios without the assistance of a computer model. We develop a novel optimization model for evaluating blood safety portfolios that enables systematic comparison of all feasible portfolios of deferral, testing, and modification interventions to identify the portfolio that is preferred from a cost-utility perspective. We present structural properties that reduce the state space and required computation time in certain cases, and we develop a linear approximation of the model. We apply the model to retrospectively evaluate U.S. blood safety policies for Zika and West Nile virus for the years 2017, 2018, and 2019, defining donor groups based on season and geography. We leverage structural properties to efficiently find an optimal solution. We find that the optimal portfolio varies geographically, seasonally, and over time. Additionally, we show that for this problem the approximated model yields the same optimal solution as the exact model. Our method enables systematic identification of the optimal blood safety portfolio in any setting and any time period, thereby supporting decision makers in efforts to ensure the safety of the blood supply.

Review of current transfusion therapy and blood banking practices

Transfusion Medicine is a dynamically evolving field. Recent high-quality research has reshaped the paradigms guiding blood transfusion. As increasing evidence supports the benefit of limiting transfusion, guidelines have been developed and disseminated into clinical practice governing optimal transfusion of red cells, platelets, plasma and cryoprecipitate. Concepts ranging from transfusion thresholds to prophylactic use to maximal storage time are addressed in guidelines. Patient blood management programs have developed to implement principles of patient safety through limiting transfusion in clinical practice. Data from National Hemovigilance Surveys showing dramatic declines in blood utilization over the past decade demonstrate the practical uptake of current principles guiding patient safety. In parallel with decreasing use of traditional blood products, the development of new technologies for blood transfusion such as freeze drying and cold storage has accelerated. Approaches to policy decision making to augment blood safety have also changed. Drivers of these changes include a deeper understanding of emerging threats and adverse events based on hemovigilance, and an increasing healthcare system expectation to align blood safety decision making with approaches used in other healthcare disciplines.

Development of a web-based application and multicountry analysis framework for assessing interdicted infections and cost-utility of screening donated blood for HIV, HCV and HBV

BACKGROUND AND OBJECTIVES

Most countries test donations for HIV, HCV and HBV using serology with or without nucleic acid testing (NAT). Cost-utility analyses provide information on the relative value of different screening options. The aim of this project was to develop an open access risk assessment and cost-utility analysis web-tool for assessing HIV, HCV and HBV screening options (http://www.isbtweb.org/working-parties/transfusion-transmitted-infectious-diseases/). An analysis for six countries (Brazil, Ghana, the Netherlands, South Africa, Thailand and USA) was conducted.

MATERIALS AND METHODS

Four strategies; (1) antibody assays (Abs) for HIV and HCV + HBsAg, (2) antibody assays that include antigens for HIV and HCV (Combo) + HBsAg, (3) NAT in minipools of variable size (MP NAT) and (4) individual donation (ID) NAT can be evaluated using the tool. Country-specific data on donors, donation testing results, recipient outcomes and costs are entered using the online interface. Results obtained include the number infections interdicted using each screening options, and the (incremental and average) cost-utility of the options.

RESULTS

In each of the six countries evaluated, the use of antibody assays is cost effective or even cost saving. NAT has varying cost-utility depending on the setting, and where adopted, the incremental cost-utility exceeds any previously defined or proposed threshold in each country.

CONCLUSION

The web-tool allows an assessment of infectious units interdicted and value for money of different testing strategies. Regardless of gross national income (GNI) per capita, countries appear willing to dedicate healthcare resources to blood supply safety in excess of that for other sectors of health care.

Blood-Borne Pathogens: A Canadian Blood Services Centre for Innovation Symposium

Testing donations for pathogens and deferring selected blood donors have reduced the risk of transmission of known pathogens by transfusion to extremely low levels in most developed countries. Protecting the blood supply from emerging infectious threats remains a serious concern in the transfusion medicine community. Transfusion services can employ indirect measures such as surveillance, hemovigilance, and donor questioning (defense), protein-, or nucleic acid based direct testing (detection), or pathogen inactivation of blood products (destruction) as strategies to mitigate the risk of transmission-transmitted infection. In the North American context, emerging threats currently include dengue, chikungunya, and hepatitis E viruses, and Babesia protozoan parasites. The 2003 SARS and 2014 Ebola outbreaks illustrate the potential of epidemics unlikely to be transmitted by blood transfusion but disruptive to blood systems. Donor-free blood products such as ex vivo generated red blood cells offer a theoretical way to avoid transmission-transmitted infection risk, although biological, engineering, and manufacturing challenges must be overcome before this approach becomes practical. Similarly, next generation sequencing of all nucleic acid in a blood sample is currently possible but impractical for generalized screening. Pathogen inactivation systems are in use in different jurisdictions around the world, and are starting to gain regulatory approval in North America. Cost concerns make it likely that pathogen inactivation will be contemplated by blood operators through the lens of health economics and risk-based decision making, rather than in zero-risk paradigms previously embraced for transfusable products. Defense of the blood supply from infectious disease risk will continue to require innovative combinations of surveillance, detection, and pathogen avoidance or inactivation.

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A symposium on blood-borne pathogens was held September 26, 2015, in Toronto, Canada.

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Transmission-transmitted infections remain a threat to the blood supply.

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The residual risk from established pathogens is small; emerging agents are a concern.

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Next generation sequencing and donor-free blood are not yet practical approaches.

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Pathogen inactivation technology is being increasingly used around the world.

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Health economic concerns will likely guide future advances in this area.

2015 proceedings of the National Heart, Lung, and Blood Institute's State of the Science in Transfusion Medicine symposium

On March 25 and 26, 2015, the National Heart, Lung, and Blood Institute sponsored a meeting on the State of the Science in Transfusion Medicine on the National Institutes of Health (NIH) campus in Bethesda, Maryland, which was attended by a diverse group of 330 registrants. The meeting's goal was to identify important research questions that could be answered in the next 5 to 10 years and which would have the potential to transform the clinical practice of transfusion medicine. These questions could be addressed by basic, translational, and/or clinical research studies and were focused on four areas: the three "classical" transfusion products (i.e., red blood cells, platelets, and plasma) and blood donor issues. Before the meeting, four working groups, one for each area, prepared five major questions for discussion along with a list of five to 10 additional questions for consideration. At the meeting itself, all of these questions, and others, were discussed in keynote lectures, small-group breakout sessions, and large-group sessions with open discourse involving all meeting attendees. In addition to the final lists of questions, provided herein, the meeting attendees identified multiple overarching, cross-cutting themes that addressed issues common to all four areas; the latter are also provided. It is anticipated that addressing these scientific priorities, with careful attention to the overarching themes, will inform funding priorities developed by the NIH and provide a solid research platform for transforming the future practice of transfusion medicine.

West Nile story: the transfusion medicine chapter

West Nile virus first arrived in North America in the late summer of 1999. Since then it has established itself in Canada and the USA, causing outbreaks every summer since then. The emergence of a new virus prompted a great deal of public health activity and posed a new challenge to the organizations that collect, test, process and supply blood products, in terms of the prevention of transfusion transmission. The rapid development and implementation of effective and innovative donor testing strategies highlights the importance of collaboration, both national and international, and creative thinking as we prepare for the future and the microbial challenges we will certainly face.