Risk-Based Decision Making: More Questions than Answers?
There is international consensus that risk-based decision making's time has come to the blood community1. Diverse groups including, the Alliance of Blood Operators (an international group of national blood systems), and more recently, the Food and Drug Administration endorse it as the appropriate framework for creating transfusion safety policies. It's hard to argue otherwise. In our arena, its foundation lies in understanding two things: resources for blood safety are limited and zero-risk is not attainable. Given the former, recognizing the latter leaves us with hard questions. At the top of the list is answering the question "How safe is safe enough?" - to which we respond, "According to whom?"
Tolerable risk is in the eye of the beholder. For example, when my daughter fractured her liver a few years back, I would gladly have consented to transfusion of red blood cells from a gay man, who was sexually abstinent for four weeks, if supplies had been tight. I think that would have represented "informed consent." But, I didn't ask her. How many other recipients or parents would have accepted the risks and provided that consent?
To provide a more current example, we must balance transfusion related acute lung injury (TRALI) risk against recent draft AABB standards requiring "blood collecting facilities" to "prevent the preparation of plasma-rich platelet components from donors known to have leukocyte antibodies or to be at increased risk of leukocyte alloimmunization." If all plasma and platelet donors must be screened for leukocyte antibodies, the donor loss would be tolerable at some centers, while it may not be at others. Current assays to test for leukocyte antibodies have poor predictive value (positive results not associated with TRALI) for this application. Our need for a robust platelet supply may be as important to some of us as the safety. At my old center, I am told that while this intervention might result in fewer TRALI cases, but with the levels of multiparity extant in Iowa, it might be associated with platelet shortages, risking more bleeding in thrombocytopenic patients. Should better control of platelet use be an alternate or additional consideration for AABB? In the face of uncertain impacts, how do you decide? More to the point, how do you allow critical stakeholders, patients, and their surrogates, to express their opinions?
There will be lots of activity in our community in coming months and years focused on building processes for risk-based decision making. ABC will participate - with enthusiasm. Let's hold ourselves accountable, from the start, for answering the question we are really asking - How much safety are we willing to "pay" for?
Louis Katz, MD, Executive Vice President, Scientific, Medical, Technical, Quality, and Regulatory; LKatz@americasblood.org
1 Bennett JL,et al. Proceedings of a consensus conference: risk-based decision making for blood safety.Trans Med Rev. 2011. 25(4):267-92