At one level, as I commented, what parents believe is irrelevant to whether it's real, and I'm not talking just about vaccines, nor suggesting that everyone who makes correlations between two events is wrong; I'm talking about the fact that the strength of a belief has nothing to do with the accuracy of the belief--I think we forget that and that many of us don't realize that. Our memories are malleable, and the connections we make may be entirely illusory despite our convictions. Once we understand that, well, I hope we become less wedded to the certainty that our recollections are entirely correct. So, when I wrote the post about AoA sounding like Jan Brady, I wasn't thinking of parental beliefs regarding causation when I wrote "that the majority of people in the autism community itself disagrees with AoA's position."
But if I were, how would I figure out where diehard AoAers were in relation to other parents of kids on the spectrum? Would I make it up? Would I estimate based on the number of AS members versus the page hits at AoA plus all the mercury/vaccine/autism yahoo groups? Yeah, it's a bit imprecise, isn't it? There's an estimated, what, 700,000 kids in the US alone with autism? Has anybody asked all these parents? No. We haven't even counted all the kids with autism; we've estimated. So, on one hand, it's fair to say, no one knows. On the other hand, it's important to see if anyone's asked.
So, what does scientific examination of the question "what do most parents of autistic children believe regarding causation" have to offer? Harrington et al. (2006) looked at a small group of parents of autistic children and found the following:
Can we reliably extrapolate out to all those hundreds of thousands of parents from a sample of 62? Well, what the heck! If 12 is good enough for the AoAers, and monkeys at that, 62 real parents ought to be proof enough! Ah, wait, though, the new Pediatrics study has "256 children with ASD and 752 controls matched by birth year, gender, and MCO," but according to many at AoA, that's not a good study at all. That's not enough of a sample to get anything. Hmmmm. Harrington et al. is a small study. It's preliminary and it would be a stretch to extrapolate out much, but we can some, enough to see that less than, let's say, a quarter of parents blamed vaccinations when this study was done.
Overall, looking at parental concerns about vaccination, in a survey of parents, only 2% of parents were concerned about the risk of autism from vaccines. It gives a pretty positive picture of how people feel about vaccination in general:
"Refusing and Delaying Vaccines
Of those surveyed, 47% reported being very comfortable/confident with their children receiving vaccinations, 43% were comfortable/confident, while 8% were not comfortable/confident, and 2% were very uncomfortable. Interestingly, the majority of both SIGNIFICANT REFUSERS and MINOR REFUSERS said they were very comfortable (25% for both groups) or comfortable (38% and 46% respectively) about their children receiving vaccinations, although the percentages are lower than among VACCINATORS WITH NO CONCERNS.
Among all respondents, 16% have refused a vaccine. Of these, 6% are MINOR REFUSERS (who refused only HepA, HPV or Flu) and 10% are SIGNIFICANT REFUSERS. Influenza and HPV being the most commonly refused (8% each), followed by Varicella (5%) and other vaccines at 2-3%.
Additionally, 13% have delayed a vaccine, with DTaP being the most commonly delayed (4% of respondents) and other vaccines at 2-3%. People who refused Hib or Polio vaccines were mostly likely to refuse other vaccines as well, while those who refused HPV or influenza refused the fewest other vaccines."I don't know that there's any convincing evidence to suggest that the majority of parents with kids on the spectrum believe it was the vaccinations, and even then, we have no way to assess the number of children with autism whose parents believe it was vaccines who actually suffered an adverse event temporally related to the vaccination (and then we still wouldn't know if it's merely an illusory correlation or an actual event). And beyond that, well, it's not something I'm interested in arguing about at the individual level, not really.
But onto other articles and tidbits of interest.
Interestingly enough, this is the introduction to an article on parents, vaccines, and fear:
"Earlier this year, the U.S. government decided to financially compensate a couple who claimed that childhood vaccines caused their daughter to develop autism (Giles, 2008). The court concluded that shots given to the child in July 2000 aggravated a pre-existing cellular disorder resulting in brain damage that included features of autism. The legal decision reignited the controversy over whether vaccines can cause autism. Researchers have failed to find a link between vaccines and autism, but parents of autistic children believe that vaccines – specifically those that contain thimerosal – trigger or cause neurological disorders (Cotliar & Levy, 2008). The court made no statement indicating the vaccines were the actual cause of the child’s autism, but supporters of the autism vaccine theory interpret the case otherwise." (Weber)After the last week coverage of the Polings, it's clear this is in reference to their case. We love our children, and cases like the Polings understandably make us fearful. It's a gamble, everything we do. There aren't any guarantees, despite how we convince ourselves there are. When we do what we believe is best, when it's what the doctors recommend, and it goes wrong, we're understandably, justifiably angry, bitter, confused. There aren't any easy answers and there sure aren't do-overs. These big decisions, and vaccines are big decisions, matter. Do we roll the dice? We do. Every day, we do. We just ignore the fact that we're doing it. We're horrible when it comes to assessing risk. Our gut gets in the way. We have to decide what to believe in, what to rely on. We'll each come to different answers for different reasons. In the end, we all have to live with ourselves, our thoughts, our actions, the consequences, whatever they may be. We ought to be able to find a measure of respect for each other, no matter how different our paths become, because we all started out on the same road, asking the same questions.
Finally, I'd like to leave you with this rather long, but important, passage from Gross (2009):
"A Bridge Too Far?
Kaufman sees the persistence of the vaccine–autism theory as a consequence of how individuals manage risk in modern society. People must trust experts to protect them from risk, whether they’re getting on an airplane or vaccinating their kids, she explains. When faith in experts erodes, personal responsibility prevails. ‘‘People think if you blindly follow experts, you’re not taking personal responsibility,’’ she adds.
Offit blames the media for keeping the myth alive by following the ‘‘journalistic mantra of ‘balance,’’’ perpetually presenting two sides of an issue even when only one side is supported by the science. And shows like ‘‘Larry King Live’’ have been ‘‘just awful on this issue,’’ he adds, placing ratings and controversy above public health by repeatedly giving McCarthy and other ‘‘true believers’’ a platform to peddle fear and misinformation. But Offit also wishes scientists would do a better job of communicating theoretical risk and the difference between coincidence and causation. Once you raise the notion of a possibility of harm, he says, ‘‘it’s hard for people to get that notion out of their head.’’
Kaufman thinks the problem is more immediate than bridging the gap between lay and expert understanding of risk. Parents treated theoretical risk as fact even as scientists tested, and ultimately rejected, the possibility that thimerosal might harm children. Thinking the institutions that were supposed to protect them from risk failed, Kaufman says, people now do their own research. But instead of leading to more certainty, she explains, ‘‘collecting more information actually increases doubt.’’
With the explosion of ‘‘contrary’’ expertise online, Kaufman says, ‘‘many parents see even the most respected vaccine experts’ perspective on the issue as just one more opinion.’’ The bulk of antivaccination Web sites present themselves as legitimate sources of scientific information, using pseudoscientific claims and emotional appeals, according to a 2002 study in Archives of Disease in Childhood . Making matters worse, the study found, nearly all sites adopted an ‘‘us versus them’’ approach, casting doctors and scientists as either ‘‘willing conspirators cashing in on the vaccine ‘fraud’ or pawns of a shadowy vaccine combine.’’ Parents’ intuitive views about vaccines were elevated above ‘‘cold, analytical science.’’ Accounts of children ‘‘maimed or killed by vaccines’’ were common—a finding that may help explain why those who advocate immunization receive death threats.
And scientists on TV and radio are hard-pressed to compete with the emotional appeals of activists. It doesn’t help that science can’t provide what some parents are looking for: the definitive study to prove that vaccines did not cause their child’s autism. ‘‘You can never say a theory’s been completely disproved, but that’s just the nature of science,’’ observes Baron-Cohen. ‘‘So for parents, that provides something to hold on to, gives hope that the theory might one day be supported.’’
As well-organized groups exploit hope and fear, parents wondering about vaccines share the fruits of their online investigations—and doubts—with moms’ groups, listservs, chat rooms, and friends. Even parents who ultimately decide to vaccinate, Kaufman says, ‘‘only feel safe if they’re on some sort of schedule that isn’t set by science.’’ ‘‘Dr. Bob’’ Sears wrote a book that gives parents a formula to delay, withhold, separate, or space out their vaccines: The Vaccine Book: Making the Right Decision for Your Child sold over 100,000 copies in just two years."
Gross, L. (2009). A broken trust: lessons from the vaccine--autism wars. Plos Biology, 7(5), e1000114. Retrieved from MEDLINE database.
Harrington, J., Patrick, P., Edwards, K., & Brand, D. (2006). Parental beliefs about autism: implications for the treating physician. Autism: The International Journal Of Research And Practice, 10(5), 452-462. Retrieved from MEDLINE database.
Weber, Carol J. "Update on autism and childhood vaccines." Urologic Nursing 28.4 (2008): 290-291. MEDLINE. EBSCO. Web. 16 Sept. 2010.