Making Theoretical Avian Flu Vaccine Choices

ANN ARBOR, Mich., May 31 - Even if there were a foolproof vaccine against avian flu during a pandemic, but with a small risk or mortality from the vaccine itself, many people say they would take their chances with the virus.

The question posed to them involved a deadly flu that is sweeping the nation, with a 10% chance of death, versus a vaccine that is completely protective, but itself carries a 5% risk of mortality.

It turns out, according to a survey, that people who imagine themselves in various roles of parent, doctor, or medical director have different responses to the tough medical choice posed by this scenario, according to Brian Zikmund-Fisher, Ph.D., of the Veterans Affairs Ann Arbor Healthcare System here.

The finding may help clinicians to guide patients to better choices, he and colleagues said.

"What we choose for ourselves is not always what we would choose for another, and reflecting on this fact may help both patients and physicians to improve their decisions," Dr. Zikmund-Fisher and colleagues said in the June issue of the Journal of General Internal Medicine.

Dr. Zikmund-Fisher and colleagues used an Internet-based survey to evaluate how people would respond to two scenarios-the deadly flu/vaccine situation and a similar case involving a slow-growing cancer and a protective but risky chemotherapy. For each scenario, the 2,399 participants were randomly assigned to consider what they course they would recommend as a patient, doctor, parent, or medical director.

In both cases, inaction carried a 10% risk of death, while active treatment-the vaccine or the chemotherapy-carried a 5% mortality risk.

In the flu scenario, the study found, only 48% of participants who imagined being the patient said they would choose the flu vaccine for themselves. On the other hand, 57% of those in a parental role would vaccinate a child, 63% of those respondents taking on medical directors role would advise a patient to be vaccinated, and 73% of those thinking as physicians would vaccinate large numbers of patients.

In the chemotherapy scenario, the pattern was similar. Sixth percent of "patients" would opt for chemotherapy for themselves, 68% of "doctors" would urge a patient to choose the regimen, as would 68% of "medical directors," and 72% of "parents" would choose chemotherapy for a child.

In both scenarios, the differences between the "patient" responses and others were statistically significant, and in the flu scenario all the pairwise differences were also statistically significant, the researchers said.

"It's very hard to see the big picture when faced with a tough medical decision," Dr. Zikmund-Fisher said in a statement. "We get wrapped up in our own situation, and that perspective makes us focus on certain aspects of problem and ignore others."

It's also common for people to try to avoid action if there's a risk of immediate harm, even though inaction may actually carry greater risks, he said-a reaction that has been dubbed "omission bias."

Many "are willing to face higher risks of death to avoid having 'caused' harm" by choosing an active treatment, such as the vaccine or chemotherapy, the researchers said.

The study illuminates some of the tensions in the doctor-patient relationship, said Peter Ubel, M.D., of the University of Michigan Medical School, a co-author.

"For the health situations we studied, (participants) actually made better decisions for other people than they made for themselves," Dr. Ubel said, and it may be that clinicians should encourage their patients to put themselves in other peoples' shoes when thinking about medical choices.

"If physicians think this way when talking with patients, they may end up helping patients by talking them into decisions-good decisions-that they otherwise would not make," Dr. Ubel said.

One limitation of the study pointed out by the authors is that "the use of Internet subjects and hypothetical scenarios may have reduced participants' motivation to take the task seriously, inflating tendencies to choose passive treatment approaches. It seems likely that people might be more survival focused when actually facing life-threatening illnesses."