Evidence Based Medicine

Putting evidence-based medicine under the microscope

Evidence based medicine is the term that has been popularized over the last 10 years or so as the primary necessary goal required for good patient care. The purpose of this phrase is of course to emphasize that we should be using the evidence from the medical literature based on thousands of studies that have been done to date to help us in our decision-making on a day to day basis when confronted with certain illnesses. I don't recall in my 30 plus years of practice when we didn't try to do this before 10 years ago, but I understand the need for its emphasis.

I wholeheartedly believe in researching, studying and applying evidence based medicine as much as we possibly can in all of our practices. We have learned much and have achieved fantastic improvements in medical care as a result of this research and application.

The difficulty occurs when we are forced by others to apply evidence based medicine where it may not be appropriate to apply it. I'm talking about health management organizations, certain insurance companies, government agencies, pay-for-performance promoters, etc.

Well-controlled, double-blinded, randomized studies are by definition performed in "well-controlled" settings so as to eliminate variables that are not being studied. In fact, this is almost a requirement for the study to be accepted as a "good study". The problem is that most of us don't practice in well controlled environments. There are a host of other variables at work that may effect the outcome. This is where the judgment of the health professional is needed to determine the best treatment regimen.

For example, if you have an 80 year-old diabetic hypertensive, osteoporotic lady with ischemic congestive heart failure (NOT an unusual combination), and if you follow evidence-based medicine guidelines, which are almost considered mandatory these days, this person will require treatment with a beta blocker, an ACE inhibitor, aspirin, long-acting nitrates, Calcium supplements, Vitamin D, a bisphosphonate, a diuretic, at least 1 or 2 diabetic medications, and a statin. All of this is required therapy for this person unless there is a specific contraindication such as severe asthma or renal failure which throws a few more variables into the equation. This amounts to a minimum of 10 medications, which according to most experts is considered "polypharmacy", and the risk of a drug interaction is so high that the use of all these medications in one individual is highly discouraged.

So the question that is asked sometimes by those of us "in the trenches" of day-to-day medicine is this: Where is the study that tells us that this 80 year-old person with all of these combinations of problems and medications is going to live longer or have a better quality of life by practicing evidence based medicine? I don't doubt the fact that if you isolate one disease treated with one medication that the outcome will be better, but this person is in a totally different situation with so many factors that can effect each other that we currently have no way of knowing whether we are doing this person any good; or even worse, we may be doing her significant harm.

While medical research has come a long way, I think we should be forever cognizant that we are still in the dark about many, many things in medicine, and that medical judgment still accounts for something, particularly in the areas where evidence may be lacking or at least unclear.

The bottom line is that medical treatment decisions should be based on the evidence that we have available, and its application should be determined by the attending physician with years of rigorous, intensive medical education, who knows what the evidence is, but who also knows his patient - not by a clerk in a government or insurance office following a procedural text.

This page was last updated on June 15, 2009.

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