Talk:Epidemiology

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Contents 1 I 2 MMR Vaccine and autism NPOV (Tagged for NPOV) 3 QUESTION Re: ==MMR Vaccine and autism NPOV (Tagged for NPOV)== 4 Causal inference section.... I have a problem with it. 5 Epidemiology as causal inference 6 MMR stuff 7 Removed unhelpful section 7.1 Yauza! What passion is here! 7.2 Steve (Kd4ttc)'s Citation of Destefano 2004 7.3 A study from Denmark 7.4 Applause for the removal of the MMR/Autism epidemiology example 8 Tools and methods 9 Bradford-Hill Guidelines 10 New article 11 Etymology

[edit] I

I respectfully suggest adding Syndemic under See also. (I came across the article and am trying to clean up/un-orphan it....) --w3steve

-- I've added some clinical areas of epik but there are, of course many others. At some point someone's really going to have to put this list in alphabetical order...? Felinity 21:55, 11 January 2007 (UTC)felnity

What does Michael Savage have to do with Epidemiology? --Claudine 06:21, 1 Mar 2004 (UTC)

I've discovered the connection. A for people seeking more information on epidemiology. --AaronW 00:45, 16 Mar 2004 (UTC)

By way of example, it is often cited that epidemiology has proven there is no link between MMR vaccine and regressive autism. For the United States, this would require a large randomized controlled trial...

This is dangerous nonsense. Science can never prove a proposition, only disprove propositions by empirical observation. The tone is highly NPOV and casts doubt on a major public health programme, with serious potential consequences. Blaise 20:26, 21 September 2005 (UTC)

Please see below for response to this and the next comment. 81.111.172.198 22:47, 3 November 2005 (UTC)

[edit] MMR Vaccine and autism NPOV (Tagged for NPOV)

I'm tagging this until it is changed to meet NPOV standards.

This is the last paragraph of Epidemiology as Casual Inference section, while it could be a good example, the way it is written is slightly POV as you can see for yourself:

By way of example, it is often cited that epidemiology has proven there is no link between MMR vaccine and regressive autism. For the United States, this would require a large randomized controlled trial, powered to detect the reported incidence of 1:160. Such a trial would establish that vaccines are (or are not) the cause of regressive Autistic Spectrum Disorders. The trial would need to be randomized ideally into three arms--a control group that receives no vaccinations, another group on the full US Centers for Disease Control immunization schedule, and a third that gets only the MMR vaccine. However, such a study has never be done and currently seems unlikely it ever will be. Accordingly, the matter would have to be established by other means, like cohort studies (where, for example, unvaccinated Amish children could serve as the control group) and/or adverse drug reaction challenge-dechallenge-rechallenge case reports.

I don't have a position on the MMR Vaccine controversey, as I don't know that much about it, but I do know that this paragraph clearly is implying that there are people who hold the position that there is no link between MMR vaccine and regressive autism and that those people are wrong. It seems to me to be clearly POV. The example serves as a good example, but I think it should be reworded so as not to be taking sides in the controversey. --Brentt 08:32, 12 October 2005 (UTC)

[edit] QUESTION Re: ==MMR Vaccine and autism NPOV (Tagged for NPOV)==

QUESTION TO Brentt RE: comments of 08:32, 12 October 2005 (UTC)

Which particular words appear to stand out as making this POV?

The words "it is often cited that epidemiology has proven there is no link between MMR vaccine and regressive autism" is a statement of fact.

What this passage appears to be saying is that, yes, these people could be wrong but it is also saying they could be right. It is also saying no one will actually know from the epidemiology alone until a sufficiently powered study is carried out and no such study has been.

That does not seem POV. That seems to be factual and is illustrating the problems inherent in the use of epidemiology. It seems a topical illustration.

See http://www.jpands.org/vol10no3/miller.pdf for an explanation of some of these issues.

25 Oct 2005 at 12:21 BST

AN ADDITION:- There also seems to be conflict between Brentt who says this is slightly POV and Blaise 20:26, 21 September 2005 (UTC) who says it is "highly NPOV" claiming that "it is often cited that epidemiology has proven there is no link between MMR vaccine and regressive autism" is dangerous nonsense. 25/10/05 19:17 BST

I think Blaise meant it is "highly POV". But anyways the problem is that it is misrepresenting the pro-MMR Vaccine side. The issue is not whether a link has been proven or disproven, in this respect the paragraph is factual: it has not been proven one way or another. The issue is whether it would be more costly, in terms of human suffering, to stop vaccination based on a possible link--considering the likely results of NOT vaccinating even if one assumes there is a link. The way the paragraph is written makes the proponents of MMR Vaccine look much more simplistic than they are. Sure, there is probably SOME people who say that the link has been "proven", but thats not really whats at issue.

(Note: When replying to a comment it makes a talk page much easier to read, and it is customary to indent--i.e. "thread"--your reply under the comment you are replying to instead of starting a whole new section. To thread, in front of each paragraph put a "::" if its a reply to a original comment or ":::" if its a reply to a reply or "::::" if its a reply to a reply of a reply etc. Also please sign your comments and replys, wiki will automatically generate your signature wherever you place four tildes [this thingy:'~'] )--Brentt 06:27, 26 October 2005 (UTC)

Thank you for the explanation. Clarity and incisiveness is needed here. The topic of this page is epidemiology. The point of this illustration is that epidemiology can never establish the issue one way or the other in individual cases, which is why if the issue is to be put to bed with finality, other evidence needs consideration.

What I think you are saying is that even if a small number do suffer adverse reactions, it is worth the risk. That is really something to be exercised on a different page because it is the risk/benefit calculation of the MMR vaccination. Perhaps a link could be established on this page to a Wiki page setting out the risks against the benefits.

Please also see "Causality Assessment of Suspected Adverse Drug Reactions" setting out advice to healthcare professionals on the assessment - http://www.medsafe.govt.nz/Profs/adverse/causality.htm. This sets out how adverse reactions are assessed. Epidemiology is not mentioned because it is not relevant to that assessment in individual cases. Epidemiology deals with the prevalence in populations.

To assess whether any number of cases do or do not exist, impartial independent clinical assessments are necessary, taken together with all other forms of evidence.

If those assessments were carried out and absolutely no causal connection were established that would put an end to the matter.

If those assessments were carried out and a causal link established officially, would parents have their children vaccinated and what would the relative risks be for vaccination against natural disease? If the risks of not having MMR against the benefits of having it are clear, then surely there would be no problem for parents? Isn't it then a 'no brainer' decision to vaccinate?

Assuming the epidemiology indicates the relative risk is too small to be revealed by epidemiology, the critics say it is not fair to parents who believe their child has been damaged by the vaccine to fail to carry through with the further investigations and just leave the matter at epidemiology, with its inherent uncertainty.

Why leave the matter uncertain? Why not follow through. Would that not deal with the matter completely?

However, those issues are for a different page. This example is explaining some of the limitations of epidemiology using a topical example people can relate to. 81.111.172.198 20:01, 28 October 2005 (UTC)

I propose to remove the POV tag from this section in no sooner than 72 hours. There appears to be cross-over of issues and the points being made suggesting this section is POV are really to do with other issues. 81.111.172.198 13:05, 19 November 2005 (UTC)

[edit] Causal inference section.... I have a problem with it.

I don't know who wrote the original article here on Wiki, but I do agree that it seems as if this section has been written with an inherent hidden agenda.

To start with, giving the example of gravity vs. smoking and lung cancer is merely an illustration of the difference between a deterministic vs. a stochastic model. Taking the first google hit on a search yields the following explanation of the difference between stochastic and deterministic models: http://www.bio.vu.nl/thb/course/tb/tb/node28.html I'm not clear as to whether the comparison of the smoking-cancer association to gravity-balls falling downward is either necessary or appropriate in an article about epidemiology. If the point, however, is that only deterministic models are causal, and that stochastic models can not be, then there is a problem here.

The idea that causality can only be assessed through randomized clinical trials (RCTs) is complete and utter rubbish. No one conducted an RCT to establish the irrefutable association between smoking and lung cancer (and Chronic Obstructive Pulmonary Disorder, and a myriad of cardiovascular diseases). There is an entire literature available on the utility and necessity for observational study and their invaluable contributions to science.

~Felinity, Epidemiologist at large.

You are quite right that RCTs may be great for treatments but are rubbish for causality. Multivariate analysis is a crude tool to suggest pathogenetic links, but the actual causality is in translational science. Here, the mechanism of epidemiologically indentified risk factors is applied to animal models, cell cultures or DNA. The proof from these studies confirms the veracity of the epidemiological link, or disproves it (in which the epidemiological link may have been caused by a confounder). JFW | T@lk 23:24, 18 December 2005 (UTC)

[edit] Epidemiology as causal inference

This section is growing more and more into a piece of POV about the MMR vaccine. This is undesirable in what is supposed to be an article giving a general overview of epidemiology, not a lengthy critique of its particular applications. I would strongly recommend a resolved epidemiological issue to be taken as an example of how epidemiological findings don't always indicate cause inference and vice versa. Given that the MMR discussion is still raging heavily, this is really a very poor example as "the jury is still out". JFW | T@lk 23:33, 21 January 2006 (UTC)

Which bits do you consider POV? Consideration can be given to your concerns and changes made to improve the item, if that is necessary?

As for length and topic, I will consider if there are better locations for the discussion of Cochrane which can then be cross-referred back to this page. Do you have any suggestions of suitable locations? How about MMR vaccine?

You are most welcome to the view that the example is not a good one and that you seek a "resolved" issue. However, that is what makes this a good example of the use of epidemiology to make a causal inference. The MMR discussion is considered to be resolved by many and resolved by use of the 5 epidemiology papers covered by the Cochrane meta-analysis. That analysis regrettably appears flawed itself for the factual reasons noted. 86.10.231.219 00:19, 22 January 2006 (UTC)

No, it's the anti-MMR crowd (such as the scientifically uninformed Melanie Phillips) who say that the analysis is flawed. There is little disagreement amongst epidemiologists that there is no link between MMR and autism. This section should be retitled "political pressure and epidemiology" or "social impact of epidemiology". Given the emotions surrounding the issue, it is actually a poor choice as the subject of this paragraph. Look at the issue of fibre and colon cancer. Fibre-rich foods decrease colon cancer, yet when adjusted for fibre content it is not the fibre that decreases the risk (JAMA 2006). Yet thousands of people eat raw fibre and think they are reducing the colon cancer risk. Now that is an example of "causal inference" proved wrong by more detailed studies, not your MMR/autism link which exists only in the minds of those who disapprove of the scientific process as a whole and will disagree with any paper that disproves this link. JFW | T@lk 16:20, 23 January 2006 (UTC)

This is a good example of ad hominem attack. It does not address the issues but makes personal attacks. It also diverts from the issues by diving off at tangents. The factual points made about errors in the Cochrane review, for example, are not addressed once. 86.10.231.219 18:28, 23 January 2006 (UTC)

The anti-vaccinationists are very good at personal attacks, so I'll be returning fire with fire. I didn't attack you, so why are you responding to me anyway? Why don't you stick to the issues are tell me exactly which points you are referring to? JFW | T@lk 18:41, 23 January 2006 (UTC)

This is all very confusing. What specific text on the Wiki Epid page are you concerned about. I cannot tell you what the issues are because you started this section on the talk page. If you do not know what the issues are that you are concerned about, I cannot reasonably be expected to be able to help you with that. Very confusing indeed. 86.10.231.219 19:06, 23 January 2006 (UTC)

The section I'm referring to is in the title of this thread, and your feigned ignorance does not help the discussion. At present, the "critcism of the Cochrane study" is unsourced and not a good case study on epidemiology as a whole. If it belongs anywhere, it should be in MMR vaccine with an adequate source to whoever first enunciated these criticisms.

But you have not answered a point I made to you: why are you taking offense at comments not made to you? JFW | T@lk 19:09, 23 January 2006 (UTC)

What are the issues in the Wiki page you want to address? The rest is not relevant to developing an encyclopedia page and is confusing. "Taking offense", "feigned ignorance" (which presumes bad faith) and suchlike is most confusing. It does not seem to take matters forward. I do hope you are not trying to provoke some kind of argument. Whilst I am sure it cannot really be the case, if it were, some might interpret it as trying to provoke a reaction so that you can accuse someone of breaking Wikipedia rules? Perhaps it might be better if you confirmed that is not the case so as to ensure no one reading your comments above gets an impression you do not intend. 86.10.231.219 21:20, 23 January 2006 (UTC)

I'm only trying to get you to stick to the point: why are you not providing a cite for the "criticism" of the Cochrane study? To give methodological criticism of a peer-reviewed study on Wikipedia is original research and unverifiable if a source for this criticism is not given. JFW | T@lk 21:39, 23 January 2006 (UTC)

Is that your only objection? Or are there any others? If it is the only objection and citations are provided are you then saying you will revert the deletions? If not, what are the other objections? Thank you for eventually acceding to my numerous requests to address the issues. 86.10.231.219 02:03, 24 January 2006 (UTC)

I agree with the drop of the NPOV tag. Kd4ttc 04:16, 24 January 2006 (UTC)

[edit] MMR stuff

Very little that has been written here on MMR is actaully useful WRT Epidemiology. --Midgley 01:23, 22 January 2006 (UTC)

See below re relevance. There also seem to be some substantial reversions and edits without any attempt at dialogue. It also comes very close on the heels of the exchange here http://en.wikipedia.org/wiki/Talk:Mumps#Midgeley_Vandalism regarding editing practices on a talk page. Perhaps just a coincidence? 86.10.231.219 05:01, 22 January 2006 (UTC)

No, Dr Midgley has an interest in epidemiology and does not like to see it misrepresented by certain elements. JFW | T@lk 16:14, 23 January 2006 (UTC)

And what does Dr Midgeley say in answer? This is the second example of questionable editing practices in almost as many days. 86.10.231.219 18:17, 23 January 2006 (UTC)

Before you sink into your familiar spiral of accusations, what edit do you find "questionable"? In what sense is he more questionable than you? JFW | T@lk 18:27, 23 January 2006 (UTC)

I agree it is helpful to avoid having accusation following accusation, so perhaps it would be better to address the issues. What issues specifically do you have regarding this Wiki page? 86.10.231.219 21:35, 23 January 2006 (UTC)

Will you now withdraw your comment that Midgley's has "questionable editing practices"? JFW | T@lk 21:44, 23 January 2006 (UTC)

You asked on my talkpage why I questioned your use of the qualification "questionable"[1]. I think this is a loaded term that should be avoided, especially if you subsequently do not substantiate your criticism. JFW | T@lk 13:04, 24 January 2006 (UTC)

I agreed with you previously that avoiding having accusation following accusation is helpful. Hence, as this page deals with Epidemiology issues, and as you do not want to leave the matter there and want to make accusations yourself, they are dealt with here [[2]] 86.10.231.219 (talk · contribs)

Suggest remove (almost) all reference to MMR issue (perhaps a small footnote at end as example of how epidemiologcal information is disputed, but first should be discussion of what it is, how it works & its history). The majority opinion (medical & health departments) is that MMR is totally unrelated to autism (accepting that there can never be proof of any negative) and thus the detractors of MMR are seen as the minority. Aside for any viewpoint on MMR itself, all may agree the media/social implications of the debate is interesting and worthy of commentary within WP. However discussion about MMR within this article is an awful example of what Epidemiology is, being a series of comments dismissing a sequence of articles accepted by others. The MMR debate has/is/will continue in the article about MMR itself, but is inappropriate within this article as it does nothing to explain what Epidemiology is or by positive example how it seeks to answer questions. If, as the anti-vaccination view point believe, there is disagreement about how epidemiology works or used to make perceived incorrect conclusions, then this should be mentioned at the end of the article as the minority viewpoint, rather than occupying a large section in the middle of the article before the epidemiology is explained. David Ruben ^Talk 03:59, 22 January 2006 (UTC)

Difficult to achieve. As a medical doctor, you will appreciate that Cochrane is a meta-analysis of epidemiology papers so an excellent example of what can go wrong with epidemiology in relation to making causal inferences. The material deleted by User Dr Midgeley set out errors in the Cochrane paper specifically bearing on the issue of causal inference and thereby demonstrating what can go wrong. The material deleted was not viewpoint but verifiable fact and the errors can be checked independently. Perhaps it might be appropriate to include references to the six epidemiology papers Cochrane cited together with the Cochrane paper reference to enable that to be done. A prior editor introduced the Cochrane paper to the page. It is familiar, topical and something easy for readers to relate to. This editor is also not an "anti-vaccinationist". All proven effective safe treatments have their place in the risk benefit equation.

As for majority and minority views, the NPOV policy is clear that all POVs need to be reflected, including minority ones. However, verifiable fact is not view and providing the references would enable the reader to make their own minds up, as Wikipedia's NPOV policy specifically states. Further, relegating differing viewpoints to the end of a page instead of putting them in contrast to what might be claimed to be "the majority" view fails to ensure balance or to ensure all viewpoint are appropriately reflected. It is a common approach adopted on Wikipedia by some POV warriors and others to ensure one POV (their preferred one) prevails over others. 86.10.231.219 05:01, 22 January 2006 (UTC)

User Dr Midgeley appears to have very strongly held POVs on these kinds of issues but he does need to accept there are other POVs and Wikipedia policy requires all to be reflected.

A wonderful example of a POV edit by him is "By way of example, MMR detractors have not been able to provide epidemiologic evidence of a link between MMR vaccine and regressive autism." Not only is this widening the issues beyond what this page is dealing with, he knows

1. the "MMR detractors" are parents of children claimed to be harmed by MMR and who have to care for those children and a number of professionals around the world none of whom are in a position to fund readily the studies necessary;
2. studies of the kind needed are beyond the funds of a relatively small number of parents on limited means and are normally carried out at the behest of governmental authorities;
3. the UK authorities withdrew funds for necessary studies;

The comment is also irrelevant to the page. In contrast, he deleted a comment adding balance which was "medical and governmental authorities have not funded the appropriate kinds of epidemiological studies needed to refute the link". In this way he ends up introducing irrelevant misleading information, removing balance and damaging the page and Wikipedia's reputation with it. This is similar behaviour to that found here http://en.wikipedia.org/wiki/Talk:Mumps#Midgeley_Vandalism where question had to be asked whether exactly the same behaviour was deliberate. User Dr Midgeley has failed to answer the question on that talk page. Is there much doubt about intention here? But let me not judge. But it would seem he needs to answer the question now. 86.10.231.219 05:01, 22 January 2006 (UTC)

• Ok I accept that the counter points of alternative POVs need to be mentioned at the point where a majority POV has been stated. However I still would urge:
  • That any discussion on the epidemiology surrounding MMR and whether it does or does not make a case for vaccination should be after Epidemiology has been fully defined. One can't critise a subject matter in a general encyclodia until one has defined the subject for the benefit of a reader who has no idea what that subject is. So perhaps mention after the description and the histoty of how its methodology developed.
  • To illustrate what Epidemiology is, there should be an uncontested example where epidemiology has provided useful insights. (MMR is a 'bad' example not because epidemiology is not being cited by both sides, but that the interpretation is so contested that a full discussion of the arguments here in this article detracts from the main focus of the article to explain what Epidemiology is).
  • Then, having given the reader enough to understand of what the aim of Epidemniology is, one can highlight methodology problems or where interesting disputes have arisen. I agree the issues surrounding MMR are a recent notable example of this - I just question the location within the article that it occurs (lower down, accepting not "at the bottom") and the length devoted to this (rather than a short NPOV outline of the issues raised by both POVs and a redirect for the main discussion to the MMR article itself) David Ruben ^Talk 02:30, 23 January 2006 (UTC)

Thanks for the sensible and considered dialogue. I will return to this when there is a moment after dealing with some other matters. This page could benefit from use of references to one of the online medical journal guides to epidemiology. I will get the references if you think that is helpful. One as I recall is certainly set at an introductory level and that may also assist in cutting things down and simplifying for readers at this level. 86.10.231.219 18:17, 23 January 2006 (UTC)

There seems to be some ad hominem attacking going on here. It lacks any close relationship to reality. For instance

"A wonderful example of a POV edit by him is "By way of example, MMR detractors have not been able to provide  
epidemiologic evidence of a link between MMR vaccine and regressive autism." Not only is this widening the issues 
beyond what this page is dealing with, he knows"

Isn't by me.Midgley 16:03, 23 January 2006 (UTC) Shall we talk about Epidemiology, not try to use every page of the encyclopedia to assert that immunisation is bad, please.Midgley 16:03, 23 January 2006 (UTC)

Good idea. Why not answer the points made? The above is diversionary.

1. Ad hominem is an attack on the person instead of dealing with the issues. The quote you cite (incompletely) above is from a specific example of POV editing. POV editing is one of the issues.
2. You deleted NPOV text and adopted this text as your own by substituting it in your very own edit. If you do not agree with its POV, then you should not have adopted it and substituted it for the prior NPOV text.
3. "It isn't by me" is little different to claiming "I didn't do it, sir" or "Its not my fault, headmaster" and is not within the range of appropriate responses;
4. No one has said immunisation is bad here except you. 86.10.231.219 18:17, 23 January 2006 (UTC)

[edit] Removed unhelpful section

I have removed the MMR vaccine as an example[3]. Old version is in the diff. As I have explained above, giving a "running case" as an example is very unhelpful. There are other examples about causal inference that could serve as better illustrations.

Another reason I removed the section is that it serves as a magnet for anti-vaccinationists, who have already caused NPOV disputes on numerous pages. Shall we let this article return to its usual calm? JFW | T@lk 19:15, 23 January 2006 (UTC)

Support; there's no reason for the "MMR controversy" to be in this article. It needs a concrete example, similar to those in the "history" section. Leaving out MMR will also help keep a NPOV. --CDN99 20:27, 23 January 2006 (UTC)

Ombudsman (talk · contribs) reverted the removal with an edit summary that does not address my concerns: "rv: wholesale deletion unmerited, given that vaccines & epidemiology are inextricably intertwined; the Cochrane whitewash exemplifies extreme measures used to quash informed debate"[4]. Vaccines and epidemiology are indeed intertwined, and epidemiology confirms that vaccines work (see the smallpox eradication by the WHO). The use of terms like "Cochrane whitewash" exactly confirms my point that this subject is much too volatile to be used as an "example" of how epidemiology cannot confirm or disprove etiology, only suggest association. JFW | T@lk 21:35, 23 January 2006 (UTC)

There are very good reasons for including in "Epidemiology as a causal inference" this recent example of epidemiology applied to an issue which, as you say, is considered to be resolved by it:-

1. Epidemiology can be used in the process of establishing a causal association but it cannot be used to establish the contrary proposition that there is no causal association at all or in any particular clinical case;
2. the example in point is one where epidemiology is being used to make the claim it proves there is no causal association;
3. no clinical evidence has been considered, as exemplified by the Cochrane review and that appears contrary to the application of the Bradford Hill criteria when assessing epidemiological evidence.
4. this particular example provokes the issue of the power of a study to detect an incidence which some papers claim is as low as 14 in 10,000 (although the confidence interval ran from 8 to 40 in 10,000 in that particular paper) and others like the US AAP and CDC say is 1 in 166;
5. it is topical, up-to-date and many readers are likely to have heard of it.

Accordingly, this issue that you say is resolved and for which you say there is no dispute among epidemiologists, is a very good example indeed to exemplify several facets of epidemiology.

It would be appropriate to give explicit reasons why you feel any particular example is "very unhelpful". You hold the view that epidemiology proves the MMR issue is resolved. It cannot therefore be considered a "running case" and the term "running case" is not appropriate because all scientific types of enquiry are "running cases", including all unproven theories and that accounts for a great deal of science.

The "serving as a magnet" reason for any minority or mainstream view is not appropriate because Wikipedia has procedures for ensuring dialogue and reasoned discussion such that anyone who comes forward with an POV view must justify it and Wikipedia NPOV policy ensures that majority and minority views must be equally represented. The same applies to the view you are putting forward, especially where you engage in wholesale deletions.

It is also confusing as progress was being made with User DavidReuben on identifying specific issues with a view to improving this Wiki Epid page. It is a shame you could not wait for dialogue to identify and then resolve any issues. Accordingly, you really do need to identify the issues and engage in dialogue before engaging is such widespread deletion.

I have no doubt that a suitable compromise for all reasonable views would have prevailed in due course. Accordingly, deletion was, it would seem premature and, I hope you do not mind too much my saying, highly POV in all the circumstances.

It is not a good answer to accuse people you do not agree with of being and "anti-this" or "anti-that" and, in my respectful opinion, is not a good or appropriate reason for wholesale deletion or indeed any significant deletion and certainly not before the matter has been fully discussed and the issues identified and argued. Here we really do need those issues identified and argued and you have now been asked very politely several times to identify those issues. 86.10.231.219 22:27, 23 January 2006 (UTC)

Those who have an issue with the Cochrane review will also have an issue with all the papers included in that review. Most of the criticism is not on methodological but ideological grounds. That is a sad fact. All those who have gone on record criticising it were known to be vaccine skeptics. I call it a "running dialogue" because obviously the book isn't closed on MMR vs. autism. Pressure groups will be demanding more evidence, and will continue to be displeased with the results. It is not a controversy in epidemiology, it is a controversy with epidemiology.

Previous discussions on many other vaccine pages, some of which you will soon learn about, have shown to me conclusively that the disagreement is not solvable along normal routes. Anti-vaccine editors (most of which do not mind bearing this label, much like I've been called a "vaccinator") have been exhibiting various forms of anti-consensus behaviour, such as being abusive in edit summaries, creating one-sided articles, inadequately citing sources and all such. It would be a pleasant surprise if you would be able to break with this dishonourable tradition.

Please provide arguments why the MMR controversy is a good example of "epidemiology as causal inference". As you have rightly spotted, it is actually an anti-example, namely that with our epidemiological tools, no causation nor inference can be constructed vis a vis MMR. Above I've provided another example (dietary fibre, which is still an open debate unfortunately), and there must be many others. JFW | T@lk 22:58, 23 January 2006 (UTC)

It would be helpful if you address the particular text that has been deleted and give reasons why you consider the particular parts deleted were objectionable.

Unless we can identify the particular parts you object to and the issues you have with those parts it will be immensely difficult making headway.

For example, which particular statements in the deleted text do you say are "ideological grounds".

Why do you disagree that the Cochrane review cites only 5 papers on autism and one paper on pervasive development disorders? Surely that is not objectionable? It is plain from the review.

If you could focus on the text you deleted from the page that would help greatly.

Some of what you say I find very confusing. You ask for example for arguments when these have already been given. And then points made also go unanswered. Would it help if you take a little more time to consider what is said and then reply? 86.10.231.219 23:26, 23 January 2006 (UTC)

[edit] Yauza! What passion is here!

Such passion is evidence of strongly held beliefs. Wikipedia benefits from so many motivated folks. I'd suggest that MMR is not an example of a general issue regarding epidemiology. However, the Autism and MMR debate is a great idea for an article such as Epidemiology of MMR vaccine and Autism or a more general Epidemiology of Autism.

As far as causality, one thing epidemiology can address is what is the upper limit of cases of Autism that could be due to MMR vaccine. For example, in the cases of the rotavirus vaccine trial, 5 cases of intusseception out of 10000 immunizations was found by epidemiologic investigation, compared to 1 case per 10000 controls. Clearly, epidemiologic tools can be quite sensitive. Actually, the study was even more sensitive, as 3 cases per 10000 were in the week after vaccination, suggesting the other two were consistent with the background rate. In the study of intussception and rotavirus, then, an epidemiologic study detected an excess rate of intusseception of only 2 cases per 10000 immunizations, which is just above the underlying rate of about 1 case per 10000. Thus, with Autism having an incidence of about 20-30 per 10000, epidemiologic tools are well equiped to find issues regarding Autism causality related to MMR. The factors such as APGAR score, maternal smoking, and other factors have been shown to be important, though, of course, are not all modifiable risk factors.

It is amusing that in an article regarding one of the most quantitative fields in all the sciences there is no quantification. There is no discussion regarding limits of sensitivity of epidemiology studies, statistical power, usual cutoff values for p value, power analysis, and sample sizes. The article really looks mostly at some large issues surrounding the use of epidemiology, but looking at the unfilled outline under Measures, the article is just breaking out of stubdom. Excellent that Snow's Broad street study was included in the article.

Kd4ttc 01:42, 24 January 2006 (UTC)

Useful suggestions for articles noted. Broadly similar suggestions had been made. Until objector states objections no point reorganising and difficult to make any progress.

With rotavirus, if I recall, there were unvaccinated controls and a lot of them, so potential for power and accuracy is higher. Confidence intervals can be much wider and accuracy much lower in other circumstances. All the difference between a micrometer and a stick to make measurements. 86.10.231.219 02:46, 24 January 2006 (UTC)

User 86.10.231.219: Please establish an identity on a user page and log in to make edits.

The studies on Autism that are based on epidemiologic approaches have unimmunized controls. Studies such as a case series suffer from referral bias, which was the basis for why Wakefield could gather a case series. The studies on autism risk factors have shown a number of factors that are much more important than any possible effect of the MMR vaccine. But this is all besides the point. There is no place for the MMR specific issues in a general talk on epidemiologic studies. There is a place for a category epidemiology that would tie everything together. Kd4ttc 03:03, 24 January 2006 (UTC)

"The studies on Autism that are based on epidemiologic approaches have unimmunized controls." I don't believe there are any 100% unimmunised controls, which is what I consider "unimmunised". "Unimmunized" I take to be with the MMR vaccine. john 13:13, 24 January 2006 (UTC)

john: You have stated a testable hypothesis. Under your hypothesis (which is the multiple immunization hypothesis) the total number of immunizations is related to the development of Autism. What studies have you looked up to address that hypothesis? Wakefield's case series suggested, however, that the MMR administration was the immunization that triggered the event, sort of a broke the camel's back hypthesis. That hypothesis would not require an unimmunized control group. Kd4ttc 14:58, 24 January 2006 (UTC)

I think not. John is I understand referring to the facet of the studies that there were no unimmunised 'controls'. One of the Cochrane MMR review authors is on record as saying:-

"Assessment of possible rare and unforeseen adverse events after vaccination is methodologically particularly difficult because independent controls are lacking in most cases. Most of the population is already vaccinated, and those who are not are likely to be unrepresentative of the reference population." 86.10.231.219 18:22, 24 January 2006 (UTC)

The comments were directed to the power of a study, a relevant topic in epidemiology. Where one study has a large exposed population and a large unexposed population, the confidence will be higher than a study where one population or the other is small or non-existent - Micrometer vs stick. It is not clear why case series and other unrelated topics are brought in to this context. 86.10.231.219 04:34, 24 January 2006 (UTC)

So, then, you haven't looked anything up? Kd4ttc 22:51, 24 January 2006 (UTC)

So, you haven't either. Touché. (And in my case is there any need? Enlighten me, please. I also take it you are not referring to the quote from the Cochrane author in your immediately preceding exchange with John?) 86.10.231.219 06:44, 25 January 2006 (UTC)

(re the Anon's comment) Touché is declared by fencers when they have been beaten by their opponent on a touch, as a courtesy to acknowledge the hit against them. However, I doubt the anon had that in mind.

John, I thought you might see this use of controls. In a study that appeared in Pediatrics._113(2)_259-66,_2004_Feb._DeStefano,_Frank._Age_at_first_measles-mumps-rubella_vaccination the following graph summarizes the findings. The experimental group was the Autistic kids. The control group were matched kids without autism. Since autism is an early onset disease, If there is a relationship between autism and MMR there should be some difference in the immunization timing between the groups. Image:Age at first measles-mumps-rubella vaccination.png Kd4ttc 21:20, 28 January 2006 (UTC)

[edit] Steve (Kd4ttc)'s Citation of Destefano 2004

This clarifies for you John - Destefano 2004 paper from "Pediatrics" cited just above [[5]] by Kd4ttc - not important. It was one of the few papers (6 only) covered in the Cochrane MMR review to deal directly with the autism issue - but see Epidemiology as a Causal Inference [[6]] (ie. the version before Midgley hacked it to death). Pretty conclusively trashes the whole thing.

Cochrane remember is the best and most authoritative these folks can do after 8 years (anniversary next month). Cochrane also said this about Destefano 2004:-

• “DeStefano 2004; provided inadequate explanations for missing data”
• “failed to report any vaccine strains (... DeStefano 2004 ....)”
• “discrepancies ... DeStefano 2004 excluded more than third of cases.”
• “Probable bias in the enrollment in MADDSP and cases may not be representative of the rest of the autistic population of the city”

The Destefano paper is also one the US CDC is involved with and therefore not one to be relied on because it is not independent. The CDC is a very partial interested party and that causes queries about funding sources and uncertainties over potential conflicts - this is a repeating problem with all the epid in this field. That is before anyone starts hacking to pieces the data and assumptions and especially all the adjustments or looking at the power of the paper and its confidence intervals or considering the desperate measures taken to bury any valid concerns about the harm being done by these vaccine programmes.

The big problem with all this epid is there is no clinical data taken into account and without that it is all useless. Now we know Krigsman and Wakefield have recently and successfully treated a kid with the worst case of IBD and autism, using anti-inflammatories and he is recovering after being refused any treatment by the UK NHS' finest from the British medical profession. I hear there are many more kids disintegrating in front of their parents' eyes but it seems most of the brave medics have their tin hats on in the trenches and won't pop their heads up for love nor money - too scared the top brass might kick 'em in the pants.

That's medicine for you. Can't think of anything more to add to the list of criticisms - too tired.

It looks a possible scenario that because this version [[7]] of Epidemiology as a Causal Inference conclusively trashes the whole thing those guys were desperate to remove it from the Epid page. I even offered to provide all the cites to substantiate and source every item too but User:Jfdwolff would not agree for it to remain even if I did. No surprises on that score I fear and supports the possible scenario mooted just above.

Yawn. I'm off to bed. Night Steve. Got to put the cat out. Appreciate your efforts. xxx "The Invisible Anon" - 86.10.231.219 23:12, 28 January 2006 (UTC)

It is beyond me why someone who can write this clearly and wants to see Autism better described in Wikipedia doesn't get a login and use it.

I'm grateful to be pointed to the old version of the epidemiology talk. The discussion on causality being in part a philosophical measure would be nice to have somewhere. MMR was a poor choice of example, though, in understanding causality implications of epidemiologic research. And the recommended approach of a prospective trial was just wrong in an article about epidemiology. Prospective trials is not what epidemiology is really about. And regarding a large prospective trial, it would be unethical to proceed without an initial epidemiologic trial to point out what prospective trial should be done. The MMR vaccine is known to provide very important protections against three serious diseases. Thus designing a trial where the controls will be assured of not being protected by the vaccine needs to be balanced by some guidance on which population to study. While someone did mention criticism of the study, there are still no epidemiologic studies that support a link to autism. Additionally, the studies that have been done are different studies with differing designs. So, while all studies have their problems, you have multiple independent measures of association of MMR and Autism, and nothing is coming up.

There is nothing new about the report above that Wakefield got a good clinical response in a kid. If you would speak to Wakefield he has at least dozens of kids like that, though last time I saw Andy was at a meeting about 2 years ago, and I am sure that his number will continue to increase. The kids I treat have done well on Asacol and Sulfasalazine, and I continue to get patients sent to me from Pfeifer treatment center. Hopefully I won't need to prescribe long term prednisone.

There is an ongoing presumption of conspiracy by many Autism-MMR enthusiasts. At autism support groups I have gone to there has been cheering from the audience when someone speaking says they think MMR causes cases of Autism The above post by someone is part of that tradition. It is a pretty bogus tradition. Wakefield's results were rapidly advertised. When the epidemiology didn't support him and further followup showed that the mercury issues were not causal a veritable cottage industry of conspiracy-outrage developed. The idea that vaccine producers are a protected class is laughable. They are subject to huge liability issues and that is one reason we are not seeing more companies getting into vaccine production. Look for example to the Rotavirus example. Due to about 2 excess deaths in 10000 vaccinations cases the vaccine was pulled. If there was a study that showed a 2 in 10000 rate of Autism we would pull the MMR. That's the history of this. The history of studies is that we haven't found evidence MMR causing autism.

If you read the Paper by DeStafano "Age at First Measles-Mumps-Rubella Vaccination in Children With Autism and School-Matched Control Subjects: A Population-Based Study in Metropolitan Atlanta" in PEDIATRICS 113(2), February 2004, 259-66 it shows that the comments made by the anon were misleading. While all studies have methodologic issues to be considered in interpretation, the concern in looking at a methodologic concern is whether there is reason to conclude that the issue raised was likely to impact the outcomes. The paper states that the 300 cases (about 1/3) that were excluded because they had moved and the immunization records were sent with them. Were there actually no vaccinations in those children there would have been even less of an association with Autism. One would have to presume that children with autism from MMR were more likely to move than children with autism unrelated to MMR. It is not known whether particular vaccine strains are important in Autism and MMR. The concern over bias in enrollment is important only if there is some systematic bias in having MMR induced cases of Autism coming to attention of the school system differently from Autism not related to Autism. The reason, then, that the anon's comments are misleading is that the anon did not discuss how the methodologic issues actually would affect the outcome of the study. They are actually unimportant when you consider how the study was constructed. Actually reading the source study is important.

Kd4ttc 22:56, 29 January 2006 (UTC)

In Reply to Kd4ttc 22:56, 29 January 2006 (UTC)

I trust you do not mind if I take a rain check on most of this discourse. Here we have what is announced to the world as the definitive review on the MMR/autism controversy and it is fundamentally flawed on a fundamental issue (and there are others). Wakefield was dealing with, for want of a better term, "PDD". Cochrane confirms none of the reviewed papers, including Destefano 2004, deal with that apart from Fombonne and that was rejected by the authors as "impossible to interpret" - which sounds pretty polite in the circumstances.

Your first main point is that there are "multiple independent measures of association of MMR and Autism, and nothing is coming up." Cochrane could find only five papers in 8 years, with Fombonne being rejected. And none are independent.

In the assessment of suspected adverse events, epidemiology is not a consideration. It forms no part of the standard criteria and guidelines for assessment of ADRs. ADR assessment is a clinical issue in individual cases. All the epid is irrelevant to assessment of ADRs.

The justification cited for the profession behaving in such a blind manner is "MMR vaccine is known to provide very important protections against three serious diseases". Having had the advantage of closely studying that issue to a depth the average medical practitioner has not, the statement does not pass muster.

Looking at this solely from an epid perspective, none of the epid cited by Cochrane is backed up by alternative forms of evidence such as clinical.

There is also no point trying to field the issue of kids being point blank refused treatment. It is illegal in the UK but it is being done. If you agree these kids' autism can be treated and put into reverse by treating IBD then why are they being left to disintegrate in the UK, the USA and Canada, (to name a few places I have had direct first hand accounts of this lack of care?).

I am not interested in "conspiracy theories", so no need to venture up that blind alley. The details of the Destefano 2004 paper do not need review (a time consuming process) for present purposes in this dialogue.

As for logins, there is little difference in this case between an IP address and a login. They are all anonymous, so there is no big deal about it. It is a non-point in this particular case, as is plain for all to see. The Invisible Anon 86.10.231.219 01:08, 30 January 2006 (UTC)

This reply by someone from an IP address shows a number of basic misunderstandings. Wakefield was dealing with Autism. A number of the papers in the Cochrane review were relevant. There were multiple independent measures. Different groups of investigators did studies in different populations. The study of Adverse Drug Reports is an epidemiologic type of study. The studies in the Cochrane review were various types of case studies, however, not review of ADRs. The anon made a mistake in characterizing the statement related to MMR having efficacy. The reference to MMR being important was not mentioned as support of MMR vaccination, but an explanation of why doing a controlled trial where MMR was withheld would be unethical. The conspiracy issue is something that the anon subscribes to. That can be seen in his posts. The anon cannot rebut the issues related to the DeStefano paper. Kd4ttc 02:24, 30 January 2006 (UTC)

In Response Steve (Kd4ttc) did exactly the same thing before when unable to defeat a successfully argued case:

• just like the preceding paragraph he sets out a barrage of unsubstantiated statements as if arguments (see second paragraph in green background text here [[8]])
• each statement shown not to support his main proposition (green background text here [[9]])
• realising he is about to be trounced and anticipating defeat he responds by threatening to delete anything further [[10]]
• the properly reasoned polite response is made in keeping with Wikipedia principles to engage in dialogue [[11]]
• he deletes it (ho hum) [[12]]
• it is pointed out this is incivility and not in accordance with Wikipedia policy [[13]]
• he claims he is being harassed and that this was a "a conversation" he did "not want to partake in" [[14]]

And here the whole exchange is summarised [[15]]

The only logical way to respond to Steve's approach is to set out the orginal propositions one by one and analyse them against Steve's (Kd4ttc) responses. Clearly, if that is done everyone can see from the above evidence where this debate over the Cochrane review is going to lead.

Aside from the incivility of the overall approach to me (the "anon") the implied threat in the last para is that he is lining up the "anon" for a complaint of harassment.

It is also worth noting another aspect of this debating style. The original points in the debate we were having on this Epidemiology talk page were about the Cochrane review. Steve has tried to move the whole dialogue away from the criticisms of the review by debating instead individual papers instead of answering the original points made.

Then there is the attempt to introduce wholly irrelevant personal issues by making allegations that he is dealing with a conspiracy theorist. Clearly a further attempt at distraction from dealing with the issues over the Cochrane review. That is aside from the implicit accusation that he is dealing with a liar who is acting in bad faith. I had earlier stated clearly that I am not interested in conspiracy theories [[16]].

Thanks Steve. The Cochrane review really looks in bad shape if this is the only way it can be defended. When you want to deal with the original points raised and debate them appropriately, let me know. I'll be sure to set aside two to three years and a couple of hundred Wikipedia pages for all the dialogue that will ensue if this is any indication of the debating style I will have to contend with. I am not sure this says much for modern medicine if this is any indication.

Got to put the cat out. Night, night Steve. xxxx The Invisible Anon 86.10.231.219 21:52, 30 January 2006 (UTC)

PS. I might start signing my postings with a PGP signature. That will guarantee they are from one source. After all, there is no magic to a Wiki signature but a PGP signature can be used anywhere, is very secure and a high level of authentication. The Invisible Anon 86.10.231.219 21:52, 30 January 2006 (UTC)

To clarify this for others just dropping by, the above post by the anon refers to an exchange in my user talk page that this anon was participating in. He made a post that was replied to, and was advised in that reply that further posts by anons would be ignored. He then posted anyway with a repetitive argument not dealing in a substantive way with issues. I told him on my talk page that I considered his repetitive, voluminous posts on my Talk page to be a form of harassment and he stopped posting there. I was glad he did. As to lengthy, repetitive posts here: well, being a talk page of an article his posts should remain. I think the anon's post speaks for itself. I apologize for an implication that the anon is lying. I think he means well. That does not exclude his seeing conspiracies. I think he was quite open with expressing his distrust of the medical profession and powerful vaccine lobbies supported by the CDC.

Given that concerns regarding the cochrane review essentially boiled down to the data that was reviewed, it makes sense to look at the data. The anon hasn't said much about the underlying studies of the Cochrane review. I still think there is no epidemiologic support for an association between the MMR vaccine and Autism or Autism Spectrum Disorders. I and many others are anxiously waiting to see if there are subgroups with Autism or some susceptibility that responde badly to the MMR. However, no one yet has been able to show that. Kd4ttc 22:30, 30 January 2006 (UTC)

[edit] A study from Denmark

A Population-Based Study of Measles, Mumps, and Rubella Vaccination and Autism. Kreesten Meldgaard Madsen, M.D., Anders Hviid, M.Sc., Mogens Vestergaard, M.D., Diana Schendel, Ph.D., Jan Wohlfahrt, M.Sc., Poul Thorsen, M.D., Jørn Olsen, M.D., and Mads Melbye, M.D. NEJM, 347(19):1477-1482.

This study came from Denmark. This study also did not find an association with Autism and MMR. The results are in the article, but table 2 has the major conclusions. In this trial they compared the development of Autism in children that received the MMR vaccine and those that did not. There was no difference in the risk of developing autism. In addition, there was no increase of Autism in the first 6 months following MMR administration. Kd4ttc 02:03, 30 January 2006 (UTC) Image:NEJM 347(19)1477-1482 Table 2.jpeg

[edit] Applause for the removal of the MMR/Autism epidemiology example

Using this article to somehow argue for or against the existence of an MMR/Autism link is entirely unencyclopedic. (This does not mean I am convinced there is no link. I would be quite interested in e.g. the results of studies as mentioned above: ... like cohort studies (where, for example, unvaccinated Amish children could serve as the control group). AvB ÷ talk 14:10, 30 January 2006 (UTC)

Yes. And it would be good, too, to move the discussion off to somewhere where there is a wider audience with interest in the Autism/MMR issue. Kd4ttc 22:32, 30 January 2006 (UTC)

[edit] Tools and methods

The article is sparse on the methods and models used in modern epidemiology. This means:

• Finding a representative sample and minimising selection bias and other sources of bias
• Forms of study, e.g. case report, case-control study, multivariate analysis
• Quantitative measures, the p value and the 95% confidence interval, the importance of the odds ratio

Ideally, someone with a grounding in epidemiology should be writing this and providing the most reliable sources. I've asked Felinity ("epidemiologist at large", above) by email, but response is still awaited. JFW | T@lk 18:07, 25 January 2006 (UTC)

There are a couple of referenced sources in case-control study from the International Journal of Epidemiology which state the controversy quite well, IM(L)O. Lawlor et. al. and Pettiti. I thinkt he controversy arises precisely because epidemiology is not a mechanism for proving cause, only for drawing inference. If you don't like the inference you tend to shoot the messenger, but honest epidemiologists (i.e. the ones I've met) don't use words like "prove" or "establish", they use qualified terms like "suggest" and "support". People are, I think, seduced by the fact that observational epidemiology helped establish the link between tobacco and smoking, but they forget that (a) there is a very strong association, much stronger than the association claimed with things like MMR and autism, and (b) it was backed bya whole raft of other kinds of evidence. I am not an expert, mind, just an amateur student of the game (my colelague Richard Keatinge is an epidemiologist). - Just zis  Guy, you know? ^[T]/_[C] AfD? 19:07, 25 January 2006 (UTC)

Guy, can't you ask Richard to start editing Wikipedia? He'll receive a warm welcome, fresh coffee and a jar of trolls. JFW | T@lk 23:54, 25 January 2006 (UTC)

Hard ot get him to do anything much outside work these days, he's rather busy. - Just zis  Guy, you know? ^[T]/_[C] AfD? 23:33, 29 January 2006 (UTC)

I concur with both above comments. In addition to the 3 issues JFW raised there are also some new trial designs that deserve mention, as well as issues surrounding noval approaches to trial termination in prospective studies. Kd4ttc 22:41, 30 January 2006 (UTC)

This page is very useful but it might be a good idea to make some sort of version that's a little less technical. Is there anyway that can be an option, just a simpler way of saying the same thing? Thank you.70.240.205.149 18:19, 14 March 2007 (UTC)Farasa

[edit] Bradford-Hill Guidelines

Greetings. I'm new here, so please forgive me if I've misformatted something. The current listing of the "Hill Criteria" seems to reinforce the commonly held notion that Hill gave these 9 criteria as bullet-points in a presentation (or carved them into stone as a list). Compared to the distilled criteria, the full text of his speech [17] may give one a very different view of causal inference in epidemiology. The distilled form of his speech has been occasionally used (distorted, misinterpreted) to attack epidemiologic studies with results counter to someone's economic interests. I think it should be made clear, with a link to the full text, that Sir Bradford-Hill never gave the criteria as listed.Epiguy 15:12, 26 March 2007 (UTC)

I agree with your point. I think that is reasonably well outlined in the last paragraph, including reference to an article that elucidates your concerns. Perhaps it should go before the list. Also, the full text of his speech is linked, but not in-line (but APA, which is more what I'm used to). But perhaps that should also be fixed up. - Limegreen 00:42, 27 March 2007 (UTC)

[edit] New article

I have created a new article, Eradication of infectious diseases, that could use a lot of work if anyone is interested. I am by no means an expert on medicine or epidemiology and the article would really benefit from the expertise of other editors. --Ginkgo100^talk 18:02, 30 November 2007 (UTC)

[edit] Etymology

I have removed the following two sentences because they did not appear to belong in the Etymology section.

It is also applied to studies of micro-organisms (microbial epidemiology). Epidemiology is also patterns of disease occurrence. From knowing information, such as who is getting the disease, when did they get the disease and where is the disease occurring will help epidemiologists infer why the disease is occurring.

If someone who knows more about epidemiology believes they belong please add them back in the appropriate place Jons63 (talk) 12:45, 27 February 2008 (UTC)