Posted by Pattie on 1/10/2011 11:37:00 AM

This month, I am participating in a ReVolution! -- Every Monday in January I plan to write a blog post here about my life and how Health at Every Size℠ has changed my life for better. This is the second installment of five.

CORRELATIONS, CAUSES AND EFFECTS

So a lesson in the modern scientific method before I get personal:

The news media loves to report about scientific studies in absolute terms. Such and such "causes" cancer or diabetes or "fill-in-the-blank-scary-disease-or-condition." Most scientific studies do not purport to establish such a strong or absolute relationship. In fact, NO SINGLE STUDY CAN EVER ESTABLISH CAUSE AND EFFECT. Here is why:

Only in rare cases is the establishment of cause and effect so solid that it can be stated in an absolute. However, science can help make a case for or against cause and effect by applying the scientific method. If enough studies are done using solid scientific methodology, then a very strong case can be made that one thing causes another thing. But three conditions have to be satisfied in order to make that case:

The "cause" has to occur in time before the "effect."

This may seem obvious, but establishing a time line is more difficult than it may appear. Just because something was observed in time before something else doesn't mean it occurred before. It just means a human paid attention to it. In medicine and health this can be particularly difficult because when a condition gets to the point of diagnosis it probably has been around for a while.

But this still remains one of the three criteria for making the case for cause and effect, so many things in health are never going to be established as anything more than related to each other.


A change in the "cause" must be met with a consistent and significant change in the "effect."

This is called correlation. It is probably the simplest and easiest criteria to establish in cause and effect because of the advances made in statistics in the 20th century. Basically, this relationship has to be tested with a sufficient enough data sample to produce results that cannot be explained by mere coincidence or random chance. So it has to be repeatedly demonstrated (which is why no one study would ever be able to solidly establish cause and effect) and that demonstration must be shown to actually be testing what it claims to test.

Small sample sizes, poor measurements or bad data collection means that correlations are not established. Data quality is very important. This includes how questions are posed. When money is involved (and it is always involved), one should take extra care to review how data collection occurred because this is where bias can be seen most often. Throwing out data that doesn't match, skewing questions and measuring techniques towards a particular conclusion and other types of biases can undermine the case made for correlation.


Once the first two criteria are established there must be NO OTHER EXPLANATION for what is being observed

That means that all other explanations should be considered and certainly that is the best reason why no one study or even a group of studies can "prove" cause and effect. All other explanations must be explored. This includes explanations about which the originators of the study can't or didn't think when they did the study.

Alternative explanations are the meat of science. It is where the debate occurs and out of it is how useful things get discovered and created. But it takes time and money to do this right, so this is where most things get subverted.


Each one of these conditions is necessary to establish a case for cause and effect. NONE of these things are singularly sufficient to establish a case for cause and effect. Yet day in and day out the news media uses the word "cause" when reporting scientific studies.

Why would news media so consistently get it wrong? Well, because, for the most part, instead of hiring a science journalist with a strong background in whatever field of science the news story comes, who can critically read the study and write intelligently about it, they just copy and paste press releases from research institutions. Often it is verbatim. So why would research institutions use the word "cause" so easily? Because, again, the person working in the public relations office is not concerned with science as much as they are with further funding and the word "cause" is often more exciting than the phrase "correlated with."

Cause is sexy. Cause sounds like a big discovery. Cause means something important has occurred with this study.

And, of course, there is also the problem in health of when do we move forward even if we can't establish cause. Epidemiology is the use of demographic information (prevalence and incidence of disease) to see patterns in diseases that allow health care workers to act effectively even if a cause and effect hasn't been firmly established. This works especially well with communicable diseases that are airborne or water-born because cutting off and quarantining the patient or the water source may in fact stop the spread of disease even if no one knows exactly which virus or bacteria is causing what. But there are definite limits to epidemiological methodologies. It does not work as well with diseases and conditions that have multiple factors.

What all this means is that you and I as both health care and media consumers have to be especially vigilant in receiving this information.

So what does this have to do with my life with HAES℠?

Before I understood these things, like many others in our society, I accepted what doctors and news media told me about my health and well-being. I figured that the system was basically honestly trying to help.

I have since learned that to be healthy I need to practice a healthy bit of skepticism. So short of becoming a biologist or spending all my waking free time researching this information, what can I do to ensure my own health?

This is my answer: Trust My Body!

Yep. And that was a big request from someone who spent a good 30 years trying to live up to an ideal that didn't fit my body. That was a big request from someone who's body is now broken from those years of trying. But I stand by it.

Science is useful but it is NOT THE ULTIMATE TRUTH. Science is a tool and like all tools, it can be used for good or for evil. Like all tools, it is only as good as the person's hands in which it resides. Like all tools, it is not perfect and can and will be improved through human effort.

Each of us has been issued a physical presence. This is a remarkable thing we have. It takes us places. It interacts with it's environment with or without our awareness. It is sensitive to and gives warning of danger. It feels pleasure as well as pain. It generally knows what it needs when it needs it and that need may or may not make sense rationally.

Health at Every Size℠ is an approach that has much scientific support, most notably, Linda Bacon's study that compared dieting versus non-dieting approaches. But like all science, Health at Every Size℠ should be studied with the skepticism and scrutiny that makes good science. In my own research, I have found that the relationship between health and size doesn't hold up to that skepticism and scrutiny well.

However, I am an advocate for Health at Every Size℠ for more than scientific reasons. My body clicks with this approach. When I was constantly dieting, I become sicker and, frankly, crazier with each dieting experience. There was no peace between me and my body. In the 10 years since I have been practicing HAES℠, I have discovered a trust in my body that has served me well. I don't fight it and even on days when I am ill and don't have the physical strength to be my most productive, I know that my body knows best.

So I invite you to learn to trust your body as well. It is a lifelong journey that begins with a simple premise: Only I know what I feel. But I assure you it is a better way to live.

Previous installments:
1. DIETING MY WAY INTO DISABILITY

1 comments:

Notblueatall said...

I love this! I think it's important for us all to be reminded that our feeling and experiences are valid. We are bombarded with marketing messages telling us not to trust out own instincts (hunger, etc). Yet everything we need to figure things out is right here *taps head* and thank the stars for that! =0)