Blood safety policy: should cautionary policies be adopted with caution?

In this issue of Blood Transfusion, nationwide studies on the prevalence of the hepatitis E virus (HEV) infection in Italian blood donors¹ and the residual risk of transfusion-transmitted hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections after the implementation of nucleic acid testing in Italy² show that the risk of transmitting infections via blood transfusion is currently very low. However, regarding the challenges the blood system faces, the risk of new and emerging pathogens (i.e. prions or viruses such as Dengue, Chikungunya, West Nile and Zika)^3–5 entering the blood supply remains. In Italy, plans for the surveillance of human vector-borne diseases were implemented after the Chikungunya outbreak in 2007⁶, along with preventive measures for reducing the risk of transmission of West Nile virus through donated blood⁷, tissues and organs. As far as HEV is concerned⁸, before considering the introduction of universal or selective HEV RNA screening of blood donations in Italy, in addition to carrying out a cost-effectiveness analysis, Spada and co-authors¹ correctly state that it would be essential to establish the true incidence of HEV infection and the related risk factors in a large representative sample of Italian blood donors.

Velati and co-authors² highlight the fact that the current risk of releasing a potentially infectious donation containing HCV or HIV into the blood supply in Italy is negligible. They conclude that blood has never been safer, but the achievement of “zero-risk” for transfusion-transmissible infections remains a goal worth pursuing. Worldwide, the “zero-risk” or “maximal safety” approach to blood supply safety has been questioned, particularly because it does not take into consideration the issue of cost. Assessing the type of economic model that is most applicable and appropriate to blood safety decisions (e.g. cost per quality-adjusted life year, cost utility, and others) is undoubtedly difficult. Several issues have to be considered when defining best practices in decision making and the ethical questions that obviously emerge⁹.

Some authors have posed the question of whether applying donor blood screening tests with incremental cost-effectiveness ratios (ICER) exceeding the general standards established in public healthcare is acceptable from an ethical point of view. They argue that while transfusion as a whole is a cost-effective intervention, some donor blood screening procedures are not¹⁰. The ICER is a statistic generally used to evaluate the cost-effectiveness of a healthcare intervention and the thresholds for its acceptability are clearly subject to political processes¹¹.

Our intention here is simply to propose a few considerations on the role of ethics in cost-effective analysis in transfusion medicine decision-making processes. We will also consider the significance of the precautionary principle in this context.

Cost-effectiveness analysis is an analytical tool used to determine how to maximize the health benefits from limited resources and has been considered as an instrument to support the decision process regarding blood screening tests¹². Basically, it assumes a utilitarian or consequentialist moral standard, or a standard of distributive justice. In the context of blood safety, if the target is reducing the risk of harm to the patient, an ICER cannot be either the normative standard or the “watershed” of the decision-making process.

Ethical principles in public health (e.g. evaluation of risks/benefits, precautionary considerations) are added to the ethical principles governing clinical care: the patient has the right to receive the best possible care and the physician’s duty of “primum non nocere”, or avoiding harming the patient, must take moral priority.

In complex decision making, cost becomes just another variable in the reasoning process, one which cannot substitute for value judgments about patients’ safety, a fundamental principle of healthcare. Patients’ safety is the reduction of risk associated with healthcare to an acceptable minimum: an acceptable minimum refers to collective beliefs of current knowledge, resources available and the context in which care is delivered, weighed against the risk of non-treatment or alternative treatment.

In this sense, screening in transfusion medicine is not comparable to a healthcare intervention but to the reduction of the risk of unnecessary harm associated with healthcare. In this sense, concrete tools for measuring cost-effectiveness must be used. We want to emphasize the fact that the choices here are not merely technical or economic but are also moral and value choices, and that ethical concerns should be integrated into cost-effectiveness models and analyses.

It is legitimate to ask whether it is appropriate to adopt the so-called precautionary principle in blood safety policy and if this principle can provide useful elements for the management of risks associated with blood transfusion. Recently, there has been increasing pressure to reconsider aggressive precautionary approaches rooted in the past¹³. Obviously, a policy which is highly unbalanced towards precaution involves the use of economic resources.

The expression “precautionary principle” as adopted in institutional documents has a precise meaning. The “precautionary principle” was formulated in the 1980s¹⁴ and initially referred to the protection of the aquatic environment¹⁵. Subsequently, it was extended to the protection of the environment in general¹⁶, before finally being transposed to the protection of human health¹⁷.

The precautionary principle is an action principle whereby public authorities are committed, without waiting for the progress of knowledge, to taking temporary and flexible measures to address potential health or environmental risks, regarding which the available scientific data are insufficient, uncertain or contradictory¹⁸. This uncertainty may concern both the extent and the probability of the risk.

Therefore, strictly speaking, the “precautionary principle” is not relevant to the topic under consideration (except possibly for emerging diseases, for which there are margins of uncertainty, as in emerging infectious disease¹⁹). However, in common language (and sometimes also in specialised literature) the expression “precautionary principle” is used in a more general sense to indicate a prudent policy applied not only to uncertain situations, but also to certain risks.

Transfusion medicine has, arguably, pioneered the use of the precautionary principle in public health safety for issues that do not have an environmental dimension¹³.

We believe it is important to emphasize the difference on a conceptual level between precaution and prevention, and between unknown risk and real risk. Precaution aims at managing uncertain risk while prevention aims at fighting certain risk²⁰.

Policy makers are committed to building a framework to implement the suitable application of precaution in transfusion medicine in the future. In 2010 the Alliance of Blood Operators (ABO) launched a project that led to the interactive risk-based decision-making framework, now available for use by blood services worldwide²¹. They claim that such a framework can help to identify, assess, act on, and communicate risk in a manner suited to every situation.

Professionals should be very clear about interventions based on the precautionary principle and revise their decision-making framework to potentially overcome a strict precautionary approach if it is no longer useful²².

Procedural justice provides that decision-makers are responsible for the reasonableness of their decisions: decision-making processes should be open, transparent and rigorous.

Based on the above, some general considerations can be proposed:

• -the “precautionary approach” to transfusion medicine has been recognised as problematic: it could be useful to explain whether and how it is inserted into an overall decision-making process and which principles and values underlie it. One of the central criteria for its application is the reversibility of decisions¹⁸. Decisions on tests to be included should be periodically updated on the basis of epidemiological data. Measures based on the precautionary principle should be maintained only while scientific information is incomplete and should be periodically reviewed and amended;

• -cost-benefit and cost-effectiveness analyses are important tools to support the decision-making process for blood screening tests. The measuring instruments must, however, be appropriate for blood safety decisions and should include ethical considerations. Work is still needed to integrate ethical concerns into cost-effectiveness measures;

• -blood screening tests differ profoundly from screening carried out in the sole interest of the individual: in this case, the recipient must be protected. Safety is, therefore, crucial: better safe than sorry;

• -blood safety is the objective of a decision-making process aimed at optimisation, while zero risk is an unattainable goal. Efforts by the reference community seek to manage potential risks, prevent real risks and clearly inform people exposed to risks (this happens especially in the informed consent process for the recipient). Making the judgments and assumptions underlying decisions explicit should have the benefit of improving the accountability of policy makers to the community they are serving.