Apathy Sketchpad

“As I said in his blog comments (assuming that he hasn’t deleted them…)”

Well he appears to have deleted (or chosen not to publish or simply lost) my comment on his deeply inappropriate MMR/road safety analogy, but given the relentlessly fallacious and woolly thinking I see in his responses to others, I am rather relieved. I doubt reasoning is likely to be enough to get through to someone willing to so blatantly shift the burden of proof:

“Now, if you refute my claim (and assert that MMR does NOT cause autism) then it is incumbent on YOU to provide the evidence.”

Andrew

Like quite a few before you, you have referred to the Cochrane review in support of your apparent stance that MMR does not cause autism. Before we get into the detail (don’t switch off yet) of this review, permit me to correct you on one quite basic point: the review did not examine 139 studies as you claim. It identified 139 studies, but actually examined just 31 of these. This is even in the abstract of the review – did you not even read the abstract? I do hope you’re a little more meticulous in your scholarly efforts with regard to your PhD.

Perhaps you can tell us how much of the review you actually did read? Assuming you read any of it at all.

Now, in the review, I can find only 6 studies that are specifically about the relationship between MMR and autism. Here are the accounts of these 6 studies as they appear in the review:

1. The study by Madsen reported no increased risk of autism or other autistic spectrum disorders between vaccinated and unvaccinated children (Madsen 2002). The interpretation of the study by Madsen was made difficult by the unequal length of follow up for younger cohort members as well as the use of date of diagnosis rather than onset of symptoms for autism (Madsen 2002).

2. The retrospective cohort study by Fombonne et al tested several causal hypotheses and mechanisms of association between exposure to MMR and pervasive development disorders (PDD). The population was made up of three cohorts of participants; one was of older children acting as the control (pre-MMR introduction). The authors concluded that there was no evidence that PDD had become more frequent, the mean age at parental concern had not moved closer to the date of exposure to MMR, there was no evidence that regression with autism had become more common, parents of autistic children with regression did not become concerned about their child in a different time frame from that of children without regression, and children with regressive autism did not have different profiles or severity to those in the control group; nor was there evidence that regressive autism was associated with inflammatory bowel disorders (Fombonne 2001).
The number and possible impact of biases in this study was so high that interpretation of the results was difficult (Fombonne 2001).

3. The retrospective person-time cohort study by Makela assessed the association between exposure to MMR and encephalitis (EN), aseptic meningitis (AM) and autism (AU) in a cohort of 535,544 Finnish children (95% of the surveillance cohort); the children were aged one to seven years at the time of vaccination. The authors compared the incidence of outcomes in the first three months after vaccination with the incidence in the following months and years. They concluded that there was no evidence of association. The study was weakened by the loss of 14% of the original birth cohort and the effects of the rather long time frame of follow up. What the impact of either of these factors was in terms of confounders is open to debate, however the long follow up for autism was due to the lack of a properly constructed causal hypothesis (Makela 2002).

4. The study by Smeeth (Smeeth 2004) assessed the association between exposure to MMR and the onset of autism and other PDD. The study was based on data from the UK’s General Practice Research Database (GPRD) which was set up on the first of June 1987. The authors concluded that their study added to the evidence that MMR vaccination was not associated with an increased risk of PDD. The odds ratio (OR) for the association between MMR vaccination and PDD was 0.78 (95% CI 0.62 to 0.97) for the non-practice matched control group and 0.86 (95% CI 0.68 to 1.09) for the practice matched control group. The findings were similar when analysis was restricted to: children with a diagnosis of autism only, to MMR vaccination before the third birthday, or to the period prior to media coverage of the hypothesis linking MMR vaccination with autism.

The study appeared carefully conducted and well reported, however, GPRD-based MMR studies had no unexposed (to MMR) representative controls. In this study the approximately 4% to 13% seemed to be unexposed controls regarded by the authors as representative. Such a small number may indicate some bias in the selection of controls.

5. This problem appeared to provide the rationale for the design of DeStefano 2004, a study assessing the association between MMR vaccine and the onset of autism. The authors compared the distribution of ages at first MMR vaccination in children with autism (cases) and controls, divided into three age strata: up to 18, 24 and 36 months. The authors concluded that there was no significant difference between cases and controls in the age at first vaccination up to 18 months (adjusted OR 0.94, 95% CI 0.65 to 1.38); and 24 months (adjusted OR 1.01, 95% CI 0.61 to 1.67); but more cases received MMR before 36 months (adjusted OR 1.23 95% CI 0.64 to 2.36; unadjusted OR 1.49, 95% CI 1.04 to 2.14) possibly reflecting the immunisation needs of children in a surveillance programme. This was a well-reported and designed study. The conclusion, however, implied bias in the enrollment of cases which may not be representative of the rest of the autistic population of the city of Atlanta, USA where the study was set.

6. The single included self-controlled case series study assessed clustering of cases of autism by postexposure periods in a cohort of 498 (with 293 confirmed cases) children (Taylor 1999). The authors reported a significant increase in onset of parental concern at six months postvaccination. The authors plausibly argued that this may have been due to multiple testing, caused by an unclear causal hypothesis, and concluded that the evidence did not support an association with autism. The study demonstrates the difficulties of drawing inferences in the absence of a non-exposed population or a clearly defined causal hypothesis.

Now, I’m going to supply this information again, this time edited in a way that leaves just the deficiencies of these studies as reported by the Cochrane reviewers. The relevance of this will be clearer when we get to the adequacy of the evidence.

1. The interpretation of the study by Madsen was made difficult by the unequal length of follow up for younger cohort members as well as the use of date of diagnosis rather than onset of symptoms for autism (Madsen 2002).

2. The number and possible impact of biases in this study was so high that interpretation of the results was difficult (Fombonne 2001).

3. The study was weakened by the loss of 14% of the original birth cohort and the effects of the rather long time frame of follow up. What the impact of either of these factors was in terms of confounders is open to debate, however the long follow up for autism was due to the lack of a properly constructed causal hypothesis (Makela 2002).

4. The study appeared carefully conducted and well reported, however, GPRD-based MMR studies had no unexposed (to MMR) representative controls. In this study the approximately 4% to 13% seemed to be unexposed controls regarded by the authors as representative. Such a small number may indicate some bias in the selection of controls (Smeeth 2004).

5. The conclusion, however, implied bias in the enrollment of cases which may not be representative of the rest of the autistic population of the city of Atlanta, USA where the study was set (DeStefano 2004).

6. The study demonstrates the difficulties of drawing inferences in the absence of a non-exposed population or a clearly defined causal hypothesis (Taylor 1999).

You are of course entitled to highlight that the reviewers did not find evidence for a causal relationship with Crohn’s disease or autism. However, seeing as the work they reviewed was epidemiological in nature, they could never have proved a causal link (only some association) anyway.

The authors of the review actually conclude, as I think they were right to do, that:

“The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate.”

Now, Andrew, that line was in the abstract too, but if you didn’t read the abstract, you wouldn’t have seen it.

Here’s another quote from the review:

“Implications for research
The design and reporting of safety outcomes in MMR vaccine studies, both pre and postmarketing, need to be improved and standardised definitions of adverse events should be adopted.”

It seems, Andrew, that you have given here a flagrant and egregious account of the Cochrane review, that has done your readers and those looking for accurate reporting on this matter a huge disservice. I note your concern about bad journalism at the end of your post. In the light of the above, and your concerns about bad journalism, will you retract it?

“A flagrant and egregious account of the Cochrane review, that has done your readers and those looking for accurate reporting on this matter a huge disservice”? Blimey. I only mentioned the report in passing — I hope you don’t expect me to thoroughly read 36 pages of review to support a single largely uncontentious sentence in a blog post. That would leave me with very little time for having fun in.

I used the 139 number purely because the sentence needed a number to scan properly. Exactly what number that was was not hugely important and if I did use an inappropriate one (which I shall try to remember to look into more properly when I have more time — really I’d want the number of papers about MMR and autism including ones that were excluded for methodological inconsistencies and I have no idea where in the document that number would be buried) I don’t think it affects the point, which is is not “there is no chance that MMR causes autism” but “there is no evidence that MMR causes autism”. It’s unreasonable to expect me to read everything ever written on the subject in case I find something and it’s equally unreasonable to expect me (and everyone else who happens to mention this widely-known fact) to systematically demolish every anti-MMR paper in the world to show it can be done — not for the sake of a blog post, certainly. Instead, I found a group of professionals who’d done largely that for me, and quoted their conclusion. I don’t think I misrepresented their conclusions when I took a quotation directly, word-for-word, from their own publication. To be honest, if the papers that conclude that MMR is safe aren’t great either then that’s a shame but doesn’t actually affect my point at all.

The strange thing is that if I’d simply stated that there was no credible evidence, with no backing at all, you wouldn’t have been able to go off on such a rant against my reference (or my use of it). Perhaps in future I should avoid trying to back up my claims with any kind of professionally published independent research and simply state things like “there’s… some experimental evidence… which supports the idea that MMR vaccination might cause autism” as fact without any supporting links at all.

Would that be okay?

A “flagrant and egregious account of the Cochrane review”.

Hehehe.

Anyway… Of 139 studies examined, the Cochrane reviewers found only 31 which met their inclusion criteria, and only 6 of those addressed the putative MMR/autism link. Okay, so the question is, Dr Briffa, how are 2 “interpretations made difficult” (not impossible), 1 “study weakened” (not destroyed), 2 “some bias”s (not hopelessly biased) and 1 “difficulty of drawing inference” (not impossibility), and the observation that the design and reporting of such studies are largely inadequate and need to be improved, incompatible with the reviewers’ finding that, “exposure to MMR was unlikely to be associated with Crohn’s disease, ulcerative colitis, autism or aseptic meningitis (mumps) (Jeryl-Lynn strain-containing MMR).” (and similar statements elsewhere)?

“A flagrant and egregious account of the Cochrane review, that has done your readers and those looking for accurate reporting on this matter a huge disservice”? Blimey. I only mentioned the report in passing — I hope you don’t expect me to thoroughly read 36 pages of review to support a single largely uncontentious sentence in a blog post. That would leave me with very little time for having fun in.”

Is this how you justify your misleading of the public and sloppy journalism? Not only did you not read all 36 pages, Andrew, you didn’t even read the abstract it seems (which would have taken all of about 2 minutes).

“I used the 139 number purely because the sentence needed a number to scan properly.”

This is really one of the lamest excuses for a crass error I have ever seen. It would be funny, but it’s not a joke, is it.

“Exactly what number that was was not hugely important”

Well that’s a matter of opinion, because I think you’re misrepresenting the extent of the evidence, which IS important.
And what’s even more important is that fact that it’s clear that you’re directly quoting from a review that even the abstract of which you have not read. That, from a journalistic and scientific standpoint, is simply unacceptable.

“and if I did use an inappropriate one (which I shall try to remember to look into more properly when I have more time — really I’d want the number of papers about MMR and autism including ones that were excluded for methodological inconsistencies and I have no idea where in the document that number would be buried)”

You’re out of your depth, Andrew, floundering – and badly.

“don’t think it affects the point, which is is not “there is no chance that MMR causes autism” but “there is no evidence that MMR causes autism”.

And there’s no good evidence that MMR doesn’t cause autism either. So, why is it you feel the need to chastise, patronise and belittle parents (‘unqualified mothers’, did you call them?) who have witnessed their child regress into an autistic state shortly after MMR vaccination? Do you think this is the right, caring way to carry on? Why the scorn? Why the apparent resentment of them? How can you not have any compassion for these people at all? Do you even know anyone like this?

“The strange thing is that if I’d simply stated that there was no credible evidence, with no backing at all, you wouldn’t have been able to go off on such a rant against my reference (or my use of it).”

Are you saying ‘I wish I hadn’t done that, now’? Because if you are, just come out and say it. Like a man.

“Perhaps in future I should avoid trying to back up my claims with any kind of professionally published independent research and simply state things like “there’s… some experimental evidence… which supports the idea that MMR vaccination might cause autism” as fact without any supporting links at all.”
Would that be okay?”

I’d already linked to it earlier in the post. Desperate, truly desperate.

Now, how about that retraction?

Consider your conscience, and you perhaps will want to set the record state regarding the findings of the Cochrane review.

And I’m not going to let this drop so don’t dodge it: what about my questions about your attitude to those who believe their child has been vaccine damaged? Will you provide some insight into this for us?

Plh

Epidemiological studies (the type reviewed in the Cochrane review) cannot be used to prove or disprove a causal link between MMR and autism. They are completely unfit for purpose as they cannot answer the question being asked here (can MMR cause autism or not?). And worse still, though it doesn’t matter much, the quality of the studies was generally poor. With me so far?

Now, if you remember it was Andrew who cited (if that’s what you can call it) the Cochrane review. He used as evidence to support the assertion that MMR does not cause autism. He has misrepresented this review by quoting extremely selectively from it, and by not putting those quotes in the context of the fact that the science reviewed was wholly inadequate to start with.

Can I ask why you think the fact that I have exposed Andrew’s gross misrepresentation of the Cochrane review is so very funny? Perhaps read his post and my two comments and then tell me what you think is so amusing. No, really.

It is so very funny, Dr Briffa, because we are well aware of the elementary fact that such studies do not disprove causal links between MMR and autism, yet you are shouting at us about it and making ridiculous and overblown claims to have exposed Andrew’s ignorance/deceit. At the same time you seem to think that (more) evidence consistent with the non-existence of a causal link has no value and you do not answer questions addressed to you on that point. The insults are not as amusing, btw.

plh

“It is so very funny, Dr Briffa, because we are well aware of the elementary fact that such studies do not disprove causal links between MMR and autism, yet you are shouting at us about it and making ridiculous and overblown claims to have exposed Andrew’s ignorance/deceit.”

“Are you serious? The Cochrane review has been wheeled out repeatedly (including here, obviously) and presented in a way that gives the impression that as far as MMR and autism is concerned, there is nothing to worry about. Actually, the review shows no such thing. And could never have anyway, on the basis of the nature of the science it reviewed. But these basic facts didn’t stop Andrew waving it like a standard for the ‘MMR is safe with regard to autism’ brigade? So don’t be too sure that everyone’s aware of the the fact that the research in the Cochrane review was not fit for purpose. Andrew didn’t appear to know, and I suspect there’s plenty more like him.

Using science in this way for what amounts to propaganda purposes is really is no laughing matter (well, certainly not for the children who might have been damaged by MMR and their parents).

“At the same time you seem to think that (more) evidence consistent with the non-existence of a causal link has no value and you do not answer questions addressed to you on that point.”

You’re alluding to evidence but not citing it, it seems. What evidence, exactly?

The Cochrane review, exactly. The “more” was in brackets because the Cochrane review is more evidence over any that came before it and has come after it. But I’m not interested in whatever other evidence there may be right now, I am interested only in why you do not value the Cochrane review findings other than the criticisms you quoted. There must be a reason otherwise your selective quoting would look rather pot-kettle-black-ish, wouldn’t it? And without a justification of the review’s valuelessness, your accusation that it has been misused for propaganda purposes looks rather silly.

“don’t think it affects the point, which is is not “there is no chance that MMR causes autism” but “there is no evidence that MMR causes autism”.

And there’s no good evidence that MMR doesn’t cause autism either. So, why is it you feel the need to chastise, patronise and belittle parents (‘unqualified mothers’, did you call them?) who have witnessed their child regress into an autistic state shortly after MMR vaccination? Do you think this is the right, caring way to carry on? Why the scorn? Why the apparent resentment of them? How can you not have any compassion for these people at all? Do you even know anyone like this?

I belittle their medical opinion because they’re wrong.

Regardless of whether or not there is a link between the MMR vaccination and autism, the people who claim the link exists do not believe this because of evidence. They believe it for emotional reasons or simply because they credulously accept anything written in what they quite wrongly class as “a newspaper”.

I don’t know anyone who thinks MMR causes autism. I suspect this is partly because most of my friends and family have degrees and are therefore sufficiently intelligent to question things that Melanie Phillips tells them, partly because I’m young enough that I know almost nobody with children, and partly because there really aren’t anything like as many anti-MMR people as the ones there are would like you to think.

“The strange thing is that if I’d simply stated that there was no credible evidence, with no backing at all, you wouldn’t have been able to go off on such a rant against my reference (or my use of it).”

Are you saying ‘I wish I hadn’t done that, now’? Because if you are, just come out and say it. Like a man.

Note to self: sarcasm lost. I’m just fascinated by the concept that I could somehow be floundering well.

I’d already linked to it earlier in the post. Desperate, truly desperate.

You mean, the primate study? Only I notice that what you actually linked to was a news item about the study, which rather suggests you didn’t bother to look up the actual paper (or surely you’d have linked to it). Fair enough, nor did I, but I’m not the one who cited it, and nor am I the one ranting about how I don’t read my references. And I’m not the one who’s telling people off for accepting the conclusions of professionals instead of investigating fully. At least my professionals were scientists and not journalists.

Now, how about that retraction?

I’m still not sure what I’m supposed to be retracting. I will, if I get chance, read the paper more carefully and retract the exact number “139″ should that prove appropriate. But I won’t retract anything because the study fails to support the idea that MMR has been proven not to cause autism, because I never so much as implied that it did.

OR DID I..?

Now, if you remember it was Andrew who cited (if that’s what you can call it) the Cochrane review. He used as evidence to support the assertion that MMR does not cause autism.

No. I never said that. I think you owe me a retraction.

I am interested only in why you do not value the Cochrane review findings other than the criticisms you quoted

I’m interested in this too: it seems to me that these are the studies that did meet the inclusion criteria, despite the criticisms: given that about a hundred didn’t I suppose that these must be mostly pretty good studies. Not perfect, nothing is, but good.

I also notice that you’ve repeatedly failed to understand my key point, which absolutely isn’t “MMR does not cause autism” but “there is absolutely no reason to suppose that MMR causes autism”. Of course, if your child had the MMR jab and then became autistic, then perhaps you have cause to suppose that — but that’s not relevant to a general scientific viewpoint. I’m not trying to be cold and dispassionate here, but that’s the reality: one anecdote, while emotionally compelling, is not evidence. And nor are a hundred anecdotes — turns out, people are stupid. They remember things according to patterns identified by psychologists as much as they do according to what really happened.

If the studies that the Cochrane collaboration looked at were totally worthless would they have made the conclusion that they showed no link between MMR vaccination and autism? Or would they have said that the data was not conclusive and they could make no judgement on the matter?

Or maybe the reviewers were paid off by shadowy persons unknown to come to that conclusion?

Andrew

“I belittle their medical opinion because they’re wrong.”

So, imagine that someone claims their child may have been vaccine damaged. They can’t be wrong really, because they’ve not claimed anything, just floating a possibility.

Now, for those that state: ‘My child’s autism is caused by MMR’, how do you KNOW they are wrong?

Because, to know they are wrong you would have to have evidence that MMR does not and cannot cause autism. And as is perfectly clear, that evidence simply does not exist.
And even if it did, is your mind open enough to accept that what we find in science may not apply to an individual? Please answer.

You cannot know any of these people are wrong, and even if they were, why do you feel the need to belittle them? Please explain?

Now, correct me if I’m wrong now, but if your stance is that you know these people ARE wrong, then logic dictates that your believe is that MMR has been proven safe. In which case, does it not seem reasonable to suggest that your citing of Cochrane was in support for that belief, yes or no?

Plh

What do you mean other than the criticisms I quoted? Is this a joke? Just six studies, all epidemiological and all quite flawed. Does this constitute good evidence to you?

And why are you not interested in any other evidence? If not now, when?

Bill
The authors in the discussion state that there was no evidence for a link between MMR and autism. Well of course not, because the evidence was completely inadequate for the purposes of finding a link (should there be one).

Forget what the reviewers wrote for a moment (like scientists aren’t fallible) and let’s apply some logic. Here’s my question to you (and to the reviewers if you like):

Do you take the fact that no link was found to be evidence that there is no link? In your mind, Bill, does absence of evidence mean evidence of absence?

Now, for those that state: ‘My child’s autism is caused by MMR’, how do you KNOW they are wrong?

Because, to know they are wrong you would have to have evidence that MMR does not and cannot cause autism. And as is perfectly clear, that evidence simply does not exist.

They think that the MMR vaccination caused their child’s autism. In fact, there is no evidence to support that claim and no reason beyond credulity and post-hoc-ergo-procter-hoc illogic to think it’s true. If their claim happens to be true, then — and this is important — their statement is accurate purely by coincidence. It’s illogical, irrational and unreasonable of them to blame the MMR vaccine for their child’s disease, because in your own words

the evidence was completely inadequate for the purposes of finding a link (should there be one).

I don’t think that reaching a technically correct conclusion via stupid reasoning counts as being “right”. And the people who mark maths exams agree with me.

I understand that raising an autistic child is difficult, and it’s not fair, and so forth (I have no children so I cannot claim to empathise with this), and I can imagine that one might understandably react by blaming something convenient. But you’d be wrong to: it’s a knee-jerk reaction to a stressful and emotional situation. I don’t mean to belittle the people so much as dismiss their medical opinions, which are ill-informed and wrong.

is your mind open enough to accept that what we find in science may not apply to an individual?

Certainly it’s true that there are some strains of bacteria resistant to the drugs we usually use to kill them; some people have allergies or other conditions and so standard medical practice would not help them — or even kill them. It’s true that in some cases vaccinations do not work and so forth. But I’d be reluctant to accept a phrase like “what we find in science may not apply to an individual” because that sort of implies that scientific laws are really just rules of thumb and don’t always apply, which is a dangerously common way to think that I wouldn’t like to promote.

Also it seems to give an all-purpose get-out clause to all crazy people: “okay, so in general there’s no risk at all, but it happened to my child anyway.” That’s clearly a moronic thing to suppose and I can’t support any statement which would lead to that supposition.

Briffa, “What do you mean other than the criticisms I quoted? Is this a joke?”

“the Cochrane review findings other than the criticisms you quoted” –plh

“exposure to MMR was unlikely to be associated with Crohn’s disease, ulcerative colitis, autism” –Cochrane review

The meaning couldn’t be clearer. You have - hypocritically - selectively quoted the criticisms and omitted the actual pertinent finding of the review, implicitly dismissing it…

“Does this constitute good evidence to you?”

…which is the whole point and the reason you need to supply a justification. The Cochrane reviewers fully justified their criticisms of aspects of the individual studies while concluding that the evidence they contained was also good enough to conclude that “exposure to MMR was unlikely to be associated with…”. You disagree. Do us (and the Cochrane review) the courtesy of justifying your assertion that the evidence was instead not good enough to support that statement.

“And why are you not interested in any other evidence? If not now, when?”

When you have provided the necessary justification for your extremely ambitious dismissal of the Cochrane review’s finding. Unless and until you do so, any discussion of other evidence would be futile. Put up or shut up, Dr Briffa :)

Andrew

“Because, to know they are wrong you would have to have evidence that MMR does not and cannot cause autism. And as is perfectly clear, that evidence simply does not exist.

They think that the MMR vaccination caused their child’s autism. In fact, there is no evidence to support that claim and no reason beyond credulity and post-hoc-ergo-procter-hoc illogic to think it’s true.”

I’m afraid you’re just wrong on this. The fact that they think this (and haven’t stated it as fact means it’s merely a hypothesis. The hypothesis still stands until it has been disproven. Which it hasn’t. So you can’t possibly know they are wrong.

“If their claim happens to be true, then — and this is important — their statement is accurate purely by coincidence. It’s illogical, irrational and unreasonable of them to blame the MMR vaccine for their child’s disease, because in your own words

the evidence was completely inadequate for the purposes of finding a link (should there be one).”

You called them ‘wrong’. And the point is there’s no possible way you could know that right now. So, it is you who are wrong (again).

“I understand that raising an autistic child is difficult, and it’s not fair, and so forth (I have no children so I cannot claim to empathise with this), and I can imagine that one might understandably react by blaming something convenient. But you’d be wrong to: it’s a knee-jerk reaction to a stressful and emotional situation. I don’t mean to belittle the people so much as dismiss their medical opinions, which are ill-informed and wrong.”

So, is it belittling or dismissing? Because you used the word belittle. And that’s closer to the truth, isn’t it? And again, how do you know these people are ill-informed. The most informed person in the world cannot tell us that MMR does not cause autism, they really can’t. So, just because someone has doubts about MMR and its safety with regard to autism does not automatically make them ill-informed. And it most certainly does not make them wrong.

“Certainly it’s true that there are some strains of bacteria resistant to the drugs we usually use to kill them; some people have allergies or other conditions and so standard medical practice would not help them — or even kill them. It’s true that in some cases vaccinations do not work and so forth. But I’d be reluctant to accept a phrase like “what we find in science may not apply to an individual” because that sort of implies that scientific laws are really just rules of thumb and don’t always apply, which is a dangerously common way to think that I wouldn’t like to promote.”

You can NEVER be assured that what you show in a scientific study will apply to another experiment where the patient in front of you is the subject of that experiment and suddenly N in that experiment is 1. This stance aptly demonstrates how flimsy your grasp of science and its application in the real world really is.

“Also it seems to give an all-purpose get-out clause to all crazy people: “okay, so in general there’s no risk at all, but it happened to my child anyway.” That’s clearly a moronic thing to suppose and I can’t support any statement which would lead to that supposition.”

What is moronic about this? Because, you’ve used the words ‘in general’ which is not absolute. So, if someone said ‘crossing the road is generally safe but I got run over today’, would that make them a moron?

Time after time you make ridiculous assertions that have no basis in truth, or fact or logic or science.

Do you think you have a sufficient grasp of the area to make informed and accurate comments? I know what I think.

The fact that they think this (and haven’t stated it as fact means it’s merely a hypothesis

In a great many cases this is false.

The hypothesis still stands until it has been disproven.

That’s what we do in physics. God, I love physics — it’s so simple. Everything’s quite black-and-white in physics. In medicine though, things are different. It’s all about correlations, p-values, stats and degrees of uncertainty. You can’t say that anything is reasonable until it’s been utterly disproved because nothing of any consequence can be disproved to that degree.

There’s good (not perfect) evidence that MMR is safe with regards to autism and there’s no credible evidence to the contrary. This hypothesis is as good as false. Scientists will acknowledge the dim possibility that it may one day transpire that a risk exists, but as of right now, the hypothesis does not “stand”.

You called them ‘wrong’. And the point is there’s no possible way you could know that right now. So, it is you who are wrong (again).

I’ve explained what I mean by “wrong”. You have chosen to apply a different (implicit) definition. Well of course I’m wrong if you arbitrarily redefine words I’ve used. That’s like saying “you say that the summit of Everest is high — but it’s never taken drugs in its life! You’re wrong!”.

Would you prefer if I said they were “almost certainly wrong, and if they’re right it’s only because by utter and hugely improbably fluke they have, by way of a series of moronically incorrect inferences from untrustworthy right-wing lunatic misinformation rags, blundered upon an unsupportable but, as it happens, technically true conclusion”? Only that seems like a very long-winded way of saying the same thing and I think you might consider it belittling them.

You can NEVER be assured that what you show in a scientific study will apply to another experiment where the patient in front of you is the subject of that experiment and suddenly N in that experiment is 1

Say a study shows that 92% of patients given treatment X for condition Y recover, compared to 28% given a placebo. You certainly can apply that knowledge to an individual: you give him the treatment because that’s almost certainly going to cure him. It may not, of course, and in that sense “what we find in science may not apply to an individual,” but I wouldn’t endorse that statement in general because it sounds more like empty anti-science rhetoric than a well-reasoned acceptance of the limits of applying blanket rules to something as varied as humanity. (Which by the way is not as varied as many pedlars of pseudoscience would like us to think.)

What is moronic about this? Because, you’ve used the words ‘in general’ which is not absolute. So, if someone said ‘crossing the road is generally safe but I got run over today’, would that make them a moron?

I can’t imagine that you genuinely didn’t know that that was not at all what I meant.

I believe that you are deliberately trying to assert an incorrect interpretation of my words so you can attack the straw-man argument you say I present rather than the actual position I hold. The really sad part of this is that even if my words do lend themselves more easily to your interpretation than my intended one, you are only attacking my articulation and not my position — essentially you’re arguing that you’re a better debater than me when you should be arguing that I’m wrong.

If you cannot understand my argument, then please admit this and I’ll try to explain it more clearly. If you can, then please either attack it or go away.

No Andrew, I’m not arguing that I’m a better debater than you. I’m demonstrating for all to see that you have a very flimsy grasp of even the most simple logic, as well as the application of scientific principles and evidence in the real world.

“God, I love physics — it’s so simple. Everything’s quite black-and-white in physics.” –Andrew

http://lambda.gsfc.nasa.gov/product/map/dr3/pub_papers/fiveyear/cosmology/wmap_5yr_cosmo.pdf

;-)

You say that, but you repeatedly ignore my position and attack my wording. I say “they’re wrong” and you repeatedly attack me for using what you see as a non-standard definition of the word ‘wrong’ instead of parsing my argument using the definition I supplied and attacking that. You have consistently misrepresented my views and arguments and almost exclusively attacked the imaginary ones which you have designed for the purpose of being attacked. It’s possible you’ll convince a few readers that way but it’s not possible that you’ll convince me that I meant something that I didn’t, so I can only conclude that either you’re pretending to argue with me and in fact just trying to persuade other people who may be reading this, or else you’re trolling.

plh,
I’d bet money that Briffa will not appreciate the humour there.

“you have a very flimsy grasp of even the most simple logic, as well as the application of scientific principles and evidence in the real world.” –Dr Briffa

Hehehe… Who holds the copyright on these posts, Andrew? Could I use that in my sig?

I don’t know. There’s a lot of debate on that on the internet…

http://www.alleyinsider.com/2008/5/who_owns_blog_comments_
http://blog.disqus.net/2008/05/30/a-commenters-rights/

You know, because of course the internet is a hot-bed of well-reasoned, qualified and well informed discussion of copyright law. I think it’s okay to use it in your sig if you own the original or delete it in 48 hours.

Use it anyway. Nobody’s going to sue, are they?

“Nobody’s going to sue, are they?”

I dunno. I think I’ll wait and see what happens to Evidencebasedeating and Mary Parsons before I risk incurring the wrath of Briffa :)

Speaking of copyright infringement, if this isn’t too large a quote it might help Dr Briffa better understand the Cochrane review (and evidence in general) and assist him with the ambitious science project he has embarked upon, or preferably, convince him to give it up:

“Suppose you are investigating ESP (extrasensory perception). A subject scores 99 correct guesses out of 100, where they would expect to get only 10 by random guesswork. However, to say that the results are consistent with the existence of ESP means nothing — they are consistent with the moon being made of green cheese, come to that. What matters is that they are not consistent (at some significance level) with the hypothesis of pure chance, leaving the alternative hypotheses of some extrasensory effect, or conscious or unconscious fraud.

“Alice discovered in Looking-Glass country that in order to get where she wanted she had to set out in the opposite direction. Likewise in statistics, if you want to show the existence of anything, you have to hypothesize the opposite, i.e. that there is no such effect. This is called the null hypothesis and written H₀. It is an Aunt Sally you set up in order to try and knock it down again. You test it, at some level of significance, and if this test fails you have supported your primary aim, as the alternative to the null hypothesis is that there is some effect there — at what level one is not required to say.

“So to show that a higher proportion of molybdenum increases the tensile strength of an alloy, or that people taking large doses of vitamin C recover from colds more quickly, or that events in a bubble chamber are due to a new species of particle, you have to hypothesize the opposite: that increased molybdenum concentration makes the alloy no stronger, that vitamin C does nothing for recovery, that the events are due to background from known processes. Paradoxically, to try and show something is there, you have to try, and fail, to assert the opposite. In statistics one cannot meaningfully accept a hypothesis: one can only reject them.

“If the test of H₀ succeeds — say your subject had only guessed 11 right out of 100 — you fail to prove the null hypothesis is false, but this does not prove that it is true. It could be that the effect is there, but at some level too small to be revealed by your experiment. You can never show that there is no effect — the best you can do is set a limit at some confidence level, as discussed in Chapter 7.” –R. J. Barlow, Statistics.

Andrew

“I can’t imagine that you genuinely didn’t know that that was not at all what I meant.”

And this, Andrew, is a glaring example of the why is it clear you do not really know what you are talking about, and have no integrity either.

It may be comforting for you to have the support of your (cyber)-friend plh, but any independent observer here I think would find you quite ridiculous. Except, I’m not sure how many truly independently-minded, enquiring individuals would actually come here for any length of time.

I can’t begin to fathom why you think it is an example of either of those things. You are becoming incoherent.

Briffa are you a lawyer?

You seem to have penchant for arguing the technicality and ignoring the merits.

If you reject epidemiology because it can’t show causation, then you have to reject anecdote as well, which is what you appear to be relying on.

You’re left in a no-mans-land of evidence where you stumble along on your intuition.

good luck.

If you aim any lower, Dr Briffa, you’ll break your knuckles on Andrew’s boots and that Cochrane review will still be standing.

Bill
You seem to have attempted to side-step my question: does absence of evidence mean evidence of absence to you?

“…does absence of evidence mean evidence of absence to you?” — Dr Briffa

So my quoting from a book on the elementary logic of statistical reasoning was in vain?

(a prima facie implausible or unlikely hypothesis, e.g. it is the tooth fairy who places a coin under your pillow when you lose a tooth, is a hypothesis which can, of course, be investigated. The more evidence that accumulates consistent with the null hypothesis - that there is no such thing as the tooth fairy and it was in fact your mum wot dunnit - the less credence one gives to the initially implausible hypothesis)

Note also that the substantive evidence of absence (aka absence of evidence in many cases), even if - and this is a crucially important point - it was not considered so implausible a hypothesis in the first place, is very far from powerless.

Oh, this is delicious. Truly nectarous. Bill “I’m a Doctor, Not a Debater!” Briffa is getting into an online argument and is, for want of a better word, trolling Andrew and deliberately dodging his argument. He’s not giving a proper response to his questions and is instead arguing semantics!

I think I’ll call for the waiter and cancel dessert. I don’t think I could possibly eat another bite.

I meant John Briffa, obviously. I don’t know, though. Bill seems more fitting.

Thats a logical fallacy, Dr.B.

The fact that it cannot be proved that MMR does not cause autism, does not mean that it does. The truth of a specific claim depends on the evidence for that claim.

There is no evidence other than anecdote, which suffers from the”Post hoc, ergo propter hoc ” fallacy. Correlation is not causation.

But you know all this and for reasons of your own, prefer to ignore it.

Ben.

What have you got against me? Confusing me with Dr. Briffa.

Ben,
I’m thinking of editing my captcha code so that a predefined list of IP addresses see new, more demeaning questions. The idea of Dr Briffa sitting there answering questions like “what letter does ‘ball’ begin with?” would amuse me immensely in a very immature way.

Dr Briffa,
If plh is one of my friends, I’ve yet to figure out which one. Perhaps you are mentally classifying anyone who agrees with you as “independent” and everyone else as my friend.

Demeaning questions, eh? I think Andrew’s trying to rile Dr Briffa. He won’t like that one bit.

No offense was intended, Bill. I sincerely apologise.

I could make fun of Briffa’s last name, but that’s more akin to his level of “debate”, where he pulls apart the semantics of an argument rather than addressing the actual point actually raised by the person actually making a statement. Actually.

Oh, and if you do implement that new Captcha, do share the code with me :)

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