Anecdotes and data: celiac disease and autism
I looked up celiac disease and autism on pubmed the other day. My mother’s secretary has a daughter recently diagnosed with autism, and diagnosed several years with celiac disease. So we were sitting in the dining room and I’m snacking and looking up stuff on pubmed.
“There’s not much research, but the two studies I’ve found on autism and celiac did not find a link, except for this one quack guy,” I say, meaning Andrew Wakefield.
“Okay,” my mom says. “So they haven’t done the research confirming it yet.”
“No,” I say. “There are two existing studies that have looked, and they did not find evidence of a link. I’m looking on pubmed, so if there were more studies they would very likely be there.”
“Ah,” my mom says. “So all we’ve got now to go on is anecdotal evidence.”
“No,” I say again. “Studies looked. They looked for a link, and they didn’t find a link, suggesting there’s not a link.”
I think at that point we detected mutually incompatible approaches to uncovering truth, and dropped the conversation.
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It’s a normal human thing to figure out what you believe is true (often by assuming anecdotes are representative of overall reality), and then seek out social back-up to help convince others of it. In this approach to truth (which drives scientists up the wall), if science is used, it is used to support one’s own truth claims to others. If someone is not trying to make truth claims to others, then there is no need for science; it doesn’t tell you anything you don’t already know.
In contrast, the role of science as-generally-agreed-upon is to test what we believe to be true to see whether it really is true. In this approach to science, science can disconfirm anecdotes, and its role is to drive what people believe, not just to back what they already do believe. So it’s much less useful for normal human goals.
Frustrating, that. Also frustrating that we don’t have much research on a lot of things. It could be true that the two studies on autism and celiac disease didn’t pick up on an actual connection…but the point is, two studies that show no connection are a lot more meaningful than no studies that show no connection.
December 30 2007 06:39 pm | |
John Fryer on 31 Dec 2007 at 5:06 am #
I detect a lot of fallacies in your blog.
1 The answer to most medical problems comes from very few sources. Dr Andrew Wakefield is more of a genius than a quack. It is not convenient to either believe his work or report it fairly.
2 Pub Med is not the complete answer for searches for truth but is probably in the pay of those with money. Journals peer reviewed but not based on the use of medicines and drugs of dubious efficiency and safety are not always found on pub med.
3 Autism may not be based on MMR but the rise of vaccine use and autism is significant. Much weaker associations are taken as proof eg 3 clinical signs and long terms in prison for SBS find more favour than 100 clinical signs that point the finger of suspicion at vaccines.
4 People are not looking for science to prove their hypothesis but they have reason to worry when pub med selects and chooses what evidence we can view. They have reason to worry when associations are buried until deselection of candidates and picking your data can change a positive correlation to the opposite.
In conclusion if we do not know what causes an illness or syndrome we need to be careful in dismissing those who have ideas of cause. Delay in finding the cause may be the very reason your mother’s secretary’s daughter has the problem because everyone has denied that exposure to 3 live viruses at the same time causes any problems to any children in any sate of health or genetic make up.
Some people richer than me offer huge sums for adults to get the same vaccines as children and not get after effects.
To date after 20 years there have been no takers let alone people silly enough to risk harm to themselves when we know most childrens vaccines are forbidden to used on adults not because they are ineffective but because of more than 50% adverse effects from those who are old enough to explain that they have a swollen head or whatever.
I can supply a very good paper that does show a rise of MMR correlates with autism and this goes against my own theory of mercury involvement which is still in many vaccines.
resonance on 31 Dec 2007 at 11:57 am #
You don’t understand how research databases work, you endorse conspiracy theories as a result of your lack of understanding, you frequently misuse scientific terminology and concepts, and your arguments are poorly worded and unclear. More problematically, though, you provide no evidence to support your claims - you simply state that they are true.
L.RabbitGirl on 01 Sep 2008 at 6:02 pm #
The thing is, there may not be a link between celiac and autism, but there may be a link between intolerance and the spectrum. Both of which can get murky.
Oh. And I didn’t have problems with a vaccine. I believe I had problems when my mom was around sick people working in a hospital. I personally think she contracted CMV, was not symptomatic, and passed it on to me while pregnant, which is a hypothesis for some cases of autism.
[THose with CMV are not necessarily, and more often aren't then are, symptomatic]
Mary on 20 Oct 2008 at 1:25 am #
This is an example of bad research leading to outrageously, misleading conclusions.
The sample sizes on these two studies were ridiculously small–only 34 controls and 34 autistic children in the larger of the two studies.
As full blown celiac disease (which means sufficiently progressed to have intestinal damage) occurs at a rate of approximately 1 in 133 in a Caucasian population the sample size was insufficient for the researchers to conclude anything about the relationship between autism and celiac disease. It is not suprising that they did not encounter any celiacs in their study, their sample size was simply too small for a meaningful result.
Furthermore, the fact that there was double the rate of antibodies related to development of celiac disease in the autistic children relative to the controls should have lead the researchers to conclude an expanded study with a larger sample size was warranted, not the bizarre conclusion that there was no link. If this is what passes for medical research on the causes of autism it is no wonder we don’t know what causes it.
resonance on 21 Oct 2008 at 6:23 am #
Mary: Interesting argument. I see you’re making a statistical argument. I’m not sure I follow you all the way through. Could you walk me through where you disagree with the authors’ use of statistics?