stat counnnter

Saturday, November 03, 2007

New Paradigm: Correlation=Causation

In my recent post "Lil' Junk Science Roundup" of 10/29, I linked to an article at JunkfoodScience.com about how epidemics are created by changing the definitions of diseases and how the definition of heart attack will soon be expanded to include detection of elevated Troponin levels. But as JFS moderator Sandy Szwarc points out, there are things other than heart attacks that can cause such elevated Troponin levels.

Now I have no problem with advances in science that expand our knowledge of reality. Maybe medical science will integrate the addition of Troponin rationally. But I do have a problem with widening the goal posts to increase one's chances of achieving a scientific/political/funding/publishing score. In that post Ms. Szwarc reveals that in 1997/98 the goal posts were moved adding millions of people to various sick or unhealthy lists. For example:
“Overweight:”Definition changed from BMI ≥ 27 to BMI ≥ 25 by the U.S. National Heart Lung and Blood Institute in 1998, instantly increasing by 43% the numbers of Americans, an additional 30.5 million, deemed ‘overweight.’
Obesity epidemic? Now you know where a large chunk of it came from. The article also shows this was done to "hypertension", "high cholesterol" and "diabetes" just to name a few.

All this demonstrates once again the truth of "Governmental encouragement does not order men to believe that the false is true, it merely makes them indifferent to the issue of truth or falsehood."-Ayn Rand.

But what does it mean to be indifferent to truth or falsehood? In what concrete forms would that manifest itself? First, we have to ask what is truth? Objectivism answers that it is that which corresponds to reality. So, if one becomes indifferent to truth and therefore reality, one will also become indifferent to the meaning of those things that identify reality--concepts and their symbols, words. Words then become nothing more than tools that one uses to get what one wants in a social context. (Whoops! My mistake. There is no longer any such thing as a context or hierarchy into which concepts are integrated. There are only paradigms which have a mysterious power to change now and then. How? Somehow.)

The meaning of words is no longer determined by reference to reality but by whatever seems to be socially acceptable in the current paradigm. Thus it should come as no surprise that another JFS article informs us that the words 'correlation' and 'association' are now deemed to have the meaning 'causal'. Ms. Szwarc informs us:
How did they define associations as being causal? They created three grades of evidence:


· Convincing: Associations deemed as strong enough evidence to call ‘convincing’ of a causal relationship included: “at least two independent cohort studies...and a plausible biological gradient (‘dose response’) in the association. Such a gradient need not be linear or even in the same direction across the different levels of exposure, so long as this can be explained plausibly.”


· Probable: They defined associations as being strong enough to label as ‘probable’ of a causal relationship if it included: “at least two independent cohort studies, or at least five case control studies” and they could find a biological plausibility.


· Limited: The label of “limited, but suggestive” included associations “too limited to permit a probable or convincing causal judgement, but where there is evidence suggestive of a direction of effect. The evidence may have methodological flaws, or be limited in amount, but shows a generally consistent direction of effect. This almost always does not justify recommendations.” It included “at least two independent cohort studies or at least five case control studies.” And evidence labeled “limited, no conclusion” was that so limited no conclusion could be made.
So, if you wish upon a star, causal is what correlation and association are. In fact, 'plausible' can even become 'convincing'. Man,what magical power these words can have if you only put them in the right paradigm. (I recommend reading the whole article. It's packed with info.)

Obviously the above is nothing more than the attempt to declare something to be causal without having to do the rigorous work usually involved in identifying a causal mechanism. For a long time now, science, the media, academe, and the body politic have treated statistical studies as if they were a substitute for actual scientific experiments. This study is an attempt to put over the notion that there is no difference, they are the same.

Expanding the goal posts of existing disease definitions by including an ever growing number of non-essentials will serve only to obliterate the essential defining characteristics of those diseases and lead to chaos in medicine. So will the packaging together of different meaning concepts and pretending they have the same meaning.

3 comments:

Myrhaf said...

This is a thought provoking post, Mike. One can infer from it that scientific method depends on a rational philosophy in order to function. I suspect David Harriman will explore this issue at length in his upcoming book on the history of modern physics.

Mike N said...

Thanks Myrhaf. I too will be looking forward to Harriman's book.

david said...

they have a financial interest in "hyping" their diseases and importance. Sad.