Evidence Based Medicine

I was listening to the news on the radio in the car on the way to work this week.  They were reporting on a newly published study that concluded that 25% of all implanted defibrillators were not supported by evidence based medicine.  The spin given by the radio reporter was that these procedures were done unnecessarily with the implication that there was a financial motive.  You will hear much more about evidence based medicine in the coming years.

This is not a new term in the medical profession and in fact, dates back to the late 1970’s.  In 1996, Dr. David Sackett defined evidence based medicine as the integration of clinical expertise and the best external evidence.  He later included patient values in this formula.  The best external evidence is what we can read about a treatment in published scientific research.  Treatment of illness or injury is in many cases guesswork.  Maybe that’s why they call it “practice,” but when you combine clinical expertise, the best external evidence, and patient values the quality of the treatment and outcome is maximized.

Today, all medical programs teach evidence based medicine.  Still, the public has not really heard of this phrase.  When you are sick or injured, you go to physical therapy, they treat you, and you get better.  You don’t think about what they are doing.  You just assume they know what they are doing and trust it will make you better.  In most cases, you are receiving evidence based medicine, but what does that really mean?

We all know that studies are being conducted and published every day to determine the best new drug, the best performing golf club, and the effect of the newest electronic device to make you feel better.  Those publications are the external evidence that Sackett referred to.  Some of those studies are good and some are poor.  Medical providers sort through all the published literature and use the best that they can find to guide their treatment.  Oftentimes, the best studies still fall short on answers.

We all believe it better to see a practitioner with a few years of experience under her belt.  We assume that the wider the scope of her experience, the more proficient she is as a provider.  There is truth to that.  Our choice would be to see someone who specializes in our particular injury with many years of experience.  That is the clinical expertise that Sackett referred to in the evidence based medicine formula.  Before there were any published studies, all medicine was based on clinical expertise.  That wasn’t long ago in the overall picture.  We’re talking about fifty or sixty years ago.

Then there are patient values.  There are certain cultural, religious, and social considerations that need to be respected in treatment.  In addition to that, each individual has unique preferences, concerns, and expectations.  Patient values are an integral part of evidence based medicine.

What we all need to remember is that the weight given to each of these three factors varies in all circumstances.  In some cases, there is a major research discovery or breakthrough that changes treatment forever.  The treatment can be effectively administered by any inexperienced practitioner with equal results to their more seasoned colleagues.  In other cases, there may be little known about an illness in the research literature.  So, the more experienced provider is generally more proficient in treatment.  Patient values play a role in outcomes as a patient may defer certain treatments or pursue others.

The trap that you should be careful not to fall into is to believe that evidence based medicine involves treatment that is only supported by what is published in the scientific journals.  Equal credit needs to be given to clinical expertise and patient values, until we know otherwise.  There is a perception in the media, insurance industry, and government that evidence based practice is driven only by the scientific journals. We must all remember that the current collection of published research has many limitation and deficiencies.  Twenty years from now, half of what we know from the current published literature will likely be invalid.  The practice of medicine will continue to always be just that, practice.  So, don’t immediately believe that all of those people with the implanted defibrillators didn’t need them.  There was clinical expertise and patient preference factored into the decision to provide that life saving treatment.  We should be careful not to allow health care policy be driven by the limited and deficient research literature without consideration of the wealth of clinical experience and patient values.