Tuesday, November 04, 2008

"I'm the decider" & the doctrine of preemptive strikes

A timely post for November 4, 2008, presidential election day in the USA...

Late night comedians have satirized George W. Bush for his "I'm the decider" statement, although what he said was true. And the U.S. President's most consequential decision appears to have been based on faulty information about weapons of mass destruction (WMD) in IraQ but it fits with his doctrine of preemptive strikes.

An informative and entertaining paper in the Oct. 1st issue of Blood, which features ASH 50th anniversary reviews, reminded me of issues surrounding being a decider and how the validity of decisions depend on the quality of information and how the precautionary principle can easily go awry.

Alter HJ, Harvey G. Klein HG. The hazards of blood transfusion in historical perspective. Blood 2008 Oct 1;112(7): 2617–26.

This paper by two giants in transfusion medicine reviews historical and current transfusion risks. From an historical perspective, as someone who worked in a blood centre when the Australian antigen (now HBsAg) was discovered and testing of blood donors was implemented, the authors' tale of its discovery revived old memories, as did their review of the entry of HIV into the blood supply.

However, this blog entry is NOT a trip down memory lane but a glimpse at what history tells us that today's transfusion recipients should expect when it comes to blood safety.

Two statements in the Blood review caught my eye because they remain topical and have ongoing relevance. The authors note that the blood bank community has been chastised for its perceived failure to act during the early days of the AIDS epidemic and outline the "real time" difficulties and pressures present during1982-84. They state:
  • "We write this not as apologists for early inaction, but to portray the immense, seemingly insurmountable dilemmas present at the time."
As an aside, I may be a bit cynical, but when someone says it's "not about the money," it almost always is, especially if they were not asked about money and bring it up out of the blue. In this case I'm sure the authors are sincere but the suspicion remains.

The second statement concerns the precautionary principle:
  • "One positive outcome of the AIDS tragedy was adoption of a new paradigm in blood transfusion, the precautionary principle, which states that 'for situations of scientific uncertainty, the possibility of risk should be taken into account in the absence of proof to the contrary' and that 'measures need to be taken to face potential serious risks.'" (definition comes from ref. 1)
What does this mean in practice? In essence, the precautionary principle is a preemptive strike.
It implies that there is a responsibility to protect the public from harm if research discovers a plausible risk, especially if it is a severe risk. Moreover, the proof of harm need not be certain and cause and effect do not need to be fully established.

In some ways the precautionary principle conflicts with an evidence-based medicine approach. To protect public safety, you do not need high-level evidence - safety is paramount and preemptive strikes are warranted. And it implies that financial considerations should not take precedence.

Put into the context of transfusion-associated HIV and hepatitis C in Canada, Justice Krever wrote (2):

  • "The slowness in taking appropriate measures to prevent the contamination of the blood supply was in large measure the result of the rejection, or at least the non-acceptance, of an important tenet in the philosophy of public health: action to reduce risk should not await scientific certainty.
  • When there was reasonable evidence that serious infectious diseases could be transmitted by blood, the principal actors in the blood supply system in Canada refrained from taking essential preventive measures until causation had been proved with scientific certainty.
  • The result was a national public health disaster."
In the aftermath of HIV and HCV, the precautionary principle has been applied to protecting the blood supply from vCJD and WNV ( 3,4). However, its application remains a challenge since it involves a volatile mix of
  • fear
  • risk
  • uncertainty
  • finite financial resources
See, for example:

Alter HJ. Pathogen reduction: a precautionary principle paradigm. Transfus Med Rev 2008 Apr;22(2):97-102. The abstract reads:
  • Although remarkable advances have been made in the prevention of the major transfusion-transmitted diseases, long intervals have transpired between the first recognition of transfusion risk and the implementation of a preventive strategy.
  • For hepatitis B virus, that interval was 30 years; for non-A, non-B/hepatitis C virus, 15 years; and for human immunodeficiency virus, West Nile virus, Trypanosoma cruzi, and bacteria, 3, 4, 5, and 18 years, respectively
  • In our existing reactive approach, there is a fundamental and inevitable delay before we can react; and thus, infections are destined to occur. The continued emergence or reemergence of transfusion-transmitted infections calls for a new paradigm of preemptive pathogen reduction (PR).
  • Two PR systems, psoralen/UV-A and riboflavin/UV-A, have shown efficacy and safety for platelets and plasma; and psoralen/UV-A technology has been successfully implemented for platelets in Europe. Pathogen reduction can eliminate or reduce the risk for any nucleic acid containing agent, including bacteria, and thus will be effective for all but prion diseases. It is possible to introduce PR for platelets and plasma now and to concentrate resources on developing PR for red cells.
  • This will require an intellectual and financial commitment from the National Institutes of Health, the Food and Drug Administration, industry, and the blood bank establishment, just as occurred for nucleic acid testing (NAT) technology. This can be done if there is sufficient will to do it.
It is inevitable that money continues to exert a strong influence on public policy decisions. But should it be the key deciding factor? It appears to have been a key concern regarding Canada's decision not to implement surrogate tests for non-A, non-B hepatitis (
  • These estimated costs of surrogate testing did not take into account the medical, economic, or societal costs that would be saved by a reduced incidence of post-transfusion non-A, non- B hepatitis if surrogate testing were implemented. Cost, without recognition of the benefits of testing, continued to dominate the discussions during the next three years about whether to implement surrogate testing in Canada....
  • The effect of the failure to implement surrogate testing in Canada is illustrated by the Blajchman–Feinman study itself, which confirmed that surrogate testing would have significantly reduced the incidence of post-transfusion hepatitis. The results of the study, published in The Lancet in 1995, support the conclusion that the implementation of both surrogate tests would have reduced the incidence of post-transfusion hepatitis by 75 per cent, and the incidence of post-transfusion hepatitis C by 85 per cent, in the period before the introduction of HCV-antibody testing in Canada.
  • The decision of the Red Cross not to implement anti-HBc and ALT testing of blood donations in Canada as surrogates for non-A, non-B hepatitis was not an acceptable one.
A related positive outcome of the AIDS tragedy not mentioned by Alter and Klein is implementation of an informed consent process specifically for transfusions.

nformed consent in general has evolved with the entire movement away from the earlier paternalism of the doctor-patient relationship in which the typically male doctor was seen as the loving father-who-knew-best who protected the child-patient. But the AIDS and hepatitis C debacle gave informed consent for transfusion a huge kick start.

Today the health care paradigm is ideally one of a team involving doctors, nurses, and other health professionals. And responsibility for medical treatment is shared, with the physician as interpreter and reliable guide, but with the patient as the ultimate decision-maker. See, for example

informed consent model was absent during the AIDS crisis of the early 1980s:
  • "From early 1983, it was clear that AHF concentrate was a risky product. The failure to tell hemophilia recipients of Factor VIII concentrate about the risks of this treatment and about alternative treatments seems especially serious in the light of present-day emphasis on the autonomy of patients in decisions involving their health." (5)
The odds are that one day we or our friends and loved ones will require a blood transfusion. As potential recipients of blood, what should we expect? We should expect
  • physicians to have used evidence-based medicine methods to select treatment options;
  • risks and benefits of transfusion to have been objectively assessed;
  • alternatives to transfusion to have been considered;
  • blood suppliers to have supplied blood components and products that are as safe as possible, including using the precautionary principle to protect the blood supply;
  • to be asked to give our consent to transfusion and that it be informed consent.

#1. If I need a blood transfusion, just like 'Dubya,' I expect to be the decider. And I expect to receive reliable unbiased information from my doctors.

But are there risks involved in too much patient "decider" autonomy? How do we achieve an effective balance?
These are topics beyond the scope of this blog entry.

#2. It's possible to interpret President Bush's decision about WMD as the precautionary principle gone awry - too much emphasis on fear and over-estimating the risk and too little on evidence-based assessments - a classic case of "err on the side of safety" with a preemptive strike gone incredibly wrong.

In contrast, in the 1980s the precautionary principle was all but ignored by blood systems around the globe with tragic results. Today the balance has shifted, but not totally.

How do we achieve the right balance of caution yet prevent paranoia, recognizing that zero risk does not exist? How do we balance fear, risk, uncertainty, and finite financial resources?
These are difficult challenges.

In the end government plays a major role, because it funds research on adverse transfusion events and hemovigilance systems, regulates the blood system, develops public health policies that affect the blood supply, and in many countries almost totally funds the blood system.

So on this U.S. election day, and on any election day anywhere, the electors are also the deciders. They get to decide who
  • best represents their concerns and philosophies on public safety issues that require balancing fear, risk, uncertainty, and resources;
  • they most trust to apply the precautionary principle and launch a judicious preemptive strike against an imminent, emerging transfusion danger.
Comments are most welcome BUT, due to excessive spam,  please e-mail me personally or use the address in the newsletter notice. 


1. Stoto MA. The precautionary principle and emerging biologic risks: lessons from human immunodeficiency virus in blood products. Semin Hematol. 2006 Apr;43(2 Suppl 3):S10-2.
2. Krever H. The blood supply system in Canada: systemic problems in the 1980s. Commission of Inquiry on the Blood System in Canada. Final report. Ottawa: Canadian Government Publishing; 1997;989.

3. Vamvakas EC, Kleinman S, Hume H, Sher GD. The development of West Nile virus safety policies by Canadian blood services: guiding principles and a comparison between Canada and the United States. Transfus Med Rev 2006 Apr;20(2):97-109.

4. Wilson K. The Krever Commission — 10 years later. CMAJ 2007 Nov 20; 177(11).

5. Leveton LB, Sox HC, Jr., Stoto MA, eds. HIV and the Blood Supply: An Analysis of Crisis Decision Making. Committee to Study HIV Transmission Through Blood and Blood Products, Institute of Medicine 1995.