I have a new study on the effectiveness of vaccine messaging with Jason Reifler, Sean Richey, and Gary Freed that is out today in Pediatrics (pre-publication version):
Effective Messages in Vaccine Promotion: A Randomized Trial
Brendan Nyhan, Jason Reifler, Sean Richey, and Gary L. Freed
Pediatrics; originally published online March 3, 2014;
DOI: 10.1542/peds.2013-2365OBJECTIVES: To test the effectiveness of messages designed to reduce vaccine misperceptions and increase vaccination rates for measles-mumps-rubella (MMR).
METHODS: A Web-based nationally representative 2-wave survey experiment was conducted with 1759 parents age 18 years and older residing in the United States who have children in their household age 17 years or younger (conducted June–July 2011). Parents were randomly assigned to receive 1 of 4 interventions: (1) information explaining the lack of evidence that MMR causes autism from the Centers for Disease Control and Prevention; (2) textual information about the dangers of the diseases prevented by MMR from the Vaccine Information Statement; (3) images of children who have diseases prevented by the MMR vaccine; (4) a dramatic narrative about an infant who almost died of measles from a Centers for Disease Control and Prevention fact sheet; or to a control group.
RESULTS: None of the interventions increased parental intent to vaccinate a future child. Refuting claims of an MMR/autism link successfully reduced misperceptions that vaccines cause autism but nonetheless decreased intent to vaccinate among parents who had the least favorable vaccine attitudes. In addition, images of sick children increased expressed belief in a vaccine/autism link and a dramatic narrative about an infant in danger increased selfreported belief in serious vaccine side effects.
CONCLUSIONS: Current public health communications about vaccines may not be effective. For some parents, they may actually increase misperceptions or reduce vaccination intention. Attempts to increase concerns about communicable diseases or correct false claims about vaccines may be especially likely to be counterproductive. More study of pro-vaccine messaging is needed.
Hi!
I think I may have some information that might help with future studies.
The divide of "pro-vaccine" and "anti-vaccine" is false. Continuing to address problems that way simply doesn't work. The question is not what parents ultimately choose. The question is how they decide. There are three main groups.
Questioners collect lots of information and decide on their own.
Delegators seek out a trustworthy expert and follow their advice. Please note that most delegators use a doctor as their expert, but some use other people as their "experts". The point is that the delegator is primarily trusting someone else's recommendation.
Simplifiers have already decided that vaccines are either all good or all bad and act accordingly. A pro-vaccine simplifier will insist on a vaccine even when there are blatant medical contraindications, because they believe that all vaccines are 100% safe and effective. An anti-vaccine simplifier will refuse all vaccines under all circumstances, because they believe that vaccines always do more harm than good. These beliefs are fervently held (on both sides) and will never be changed by reason or argument because the core driving reason is fear. Pro-vaccine simplifiers are terrified of disease, often because they have personal experience with a tragedy. Anti-vaccine simplifiers are terrified of vaccines, often because they have personal experience with a tragedy. Trying to address fear and grief with facts and statistics doesn't work. Never has, never will.
Fortunately, there aren't a lot of simplifiers, even when you combine both types. They're noisy and tend to be grossly overrepresented in both politics and journalism, but they aren't actually that common. There is not this huge wave of anti-vaxxers. That is a myth.
What is real is that you have a huge shift in all of health care from delegators to questioners. Most parents these days do not want to passively follow a doctor's orders. Most parents want to be involved in the decision-making.
And that's important because the same strategies that are reassuring to a delegator are alarming to a questioner (and vice-versa). When a doctor says "just trust me", a delegator is likely to be reassured. A questioner is likely to be offended and suspicious. On the flip side, a doctor who provides lots of information and asks the patient about their values will delight a questioner. However, it will scare a delegator, who will begin to question the doctor's expertise if they don't even have the confidence to give clear instructions.
Oh and trying to scare a questioner into compliance is a really, really bad tactic. Nothing will turn a questioner away faster that scare tactics.
Which perfectly matches the results of this study. The "worst case scenarios" of measles are scare tactics.
The "disease risks" was factual information, but unlikely to be new to any of the study participants.
The "autism link" was likely to be new and interesting information, which questioners crave. Thus the positive results.
Why does nothing show a positive change for vaccination? Well that's pretty simple:
The simplifiers aren't going to do anything but get more certain in their beliefs. Changing a simplifier's mind is akin to a religious conversion. It's not going to happen because of a public-health message.
The delegators are following directions from a trusted expert, and not going to do much except bring this information to their expert. Who has probably already seen it and already has an opinion.
The questioners are looking for how to evaluate risk vs. benefit for their child. "Vaccines are safe and effective" is an overall average. If you want to get a questioner to choose a vaccine for their child, you need to discuss individual risk vs. benefit. And there was not a single message about that.
I would love to get the simplifiers/delegators/questioners hypothesis evaluated, because (if true) I think it could significantly improve the efficacy of public health campaigns. Please feel free to contact me or just pass the information on to someone who will do something with it.
Posted by: Karen Crisalli Winter | March 07, 2014 at 03:07 PM