May 14, 2019

Evidence Based Medicine is Less than 50 years old: born in Hamilton Ontario from an American doctor who made Canada home.

If you should poll students and scholars of medical history about the most important developments of modern health care, you would find something called Evidence-Based Medicine (EBM) will be very high up on the list. That is the delivery and choices of medical treatments based on sound evidence. Based on scientific evaluation. Based on firm unbiased evaluation such as in double-blind clinical trials and ones that include placebo groups. Now, this seems logical to any of the medical students, ophthalmology residents and retinal fellows I teach about genetics, molecular biology and research in 2019.  Yet physicians born in the early 1990s were often under the care of medical doctors whose choices of treatments were not necessarily sound options based on unbiased evaluation of the evidence. Yes, over 20 years after humans first walked on the Moon, medical schools and the bodies that license physicians were promoting practices that had often evolved on their own over decades with some backed up by scientific examination but many that were not. Fortunately for us now, an American doctor moved to Canada in the 1960s just as universal healthcare was started nationwide and he realized that was the climate to established principals now considered essential to the teaching and practice of medicine. Evidence-Based Medicine. Who was this American who made Canada his home?

David Sackett, MD, was born in Chicago in 1934 and died in 2015. He would become the focus of a series of fortunate events that helped us get to the scientific practice of medicine today. "An alignment of all the correct stars", so to speak. For one thing, he not only obtained a medical degree from the University of Illinois and specialization in internal medicine and nephrology (kidney), but he took more education in a topic few MDs bothered with. Dr. Sackett got a Masters degree in Epidemiology from Harvard University and practiced in several US cities before moving to take up a Chairmanship at McMasters University in Hamilton, Ontario. The department he founded in 1967 at this very new upstart Canadian medical school was the first full Department of Clinical Epidemiology in the world. Canada was 100 years old in 1967, its Centennial year, he was 32, and the country's universal health care system had just rolled out around the nation. First tested by the province of Saskatchewan, the basic premise was simple. Provinces (Canada's equivalence of a State), were left to decide how they wanted to run their health insurance for their residents, as long as they met some fundamental minimum services. The most fundamental one was simple. If you lived in a Canadian province, you were automatically in their health insurance plan. Much as in the United States for those of us with health care plans supported through our employers, Canadians have health insurance premiums sent to the insurance program from their pay. Another important fundamental property of Canadian health insurance was that residents remain covered by health insurance even between jobs, even when unemployed, or when in training (college students) and not making high wages. 

With his training, interests, and this particular Canadian environment, insurance for every citizen, a new medical school that dared to promote Epidemiology to Department status, Dr. Sackett could see a fundamental keystone that would be required to ensure that this great Canadian experiment would find success. There were medical and public management policy experts in Canada that were already promoting the idea of applying scientific evidence concepts to health care practice and delivery. Sackett had experience seeing the poorer populations of large cities he had worked in simply unable to benefit from access to basic health care. In the new Canadian system, he saw the solution to deliver health care to everyone and also knew that too many practices that were not based on evidence, so much as tradition, would tend to waste resources and not necessarily improve public health. As an epidemiologist, he understood the necessity to scientifically test and evaluate medical practice options and public health processes to truly give the patient treatment options that were backed by evidence. Proof that they were not guesses or even snake oil. Maybe not perfect, but treatments that could deliver benefits to the patient that far exceeded any risk of harm. While there were many physicians who would be quick to agree with Dr. Sackett that only properly tested treatments with proof, such as from clinical trials, should be part their toolset, this idea was not mandatory nor applied by consensus to medical educations or practices around North America.

By 1981, Dr. Sackett led a group of Epidemiologists at McMasters who published several papers on the idea of Evidence-Based Medicine in the Journal of the Canadian Medical Association. Not long before, in 1976, the Levels of Evidence (LOE) system was developed by a Canadian Task Force on Periodic Health Examination formed by the Health Ministries of Canada's ten Provincial Governments. This system was a basic grading system for the kinds of evidence available for any medical treatment or procedure with grade A being the best kind.

Dr. Sackett and colleagues revised a version of the LOE system several years later and again with a grading system. Grade A, no surprise, is a Level I: Large randomized controlled trial, with clear results, low risk of error, and controls. Randomization is important in clinical trials. It is the process where patients are assigned by a random process to the treatment test group or a control group. The control group is either a current treatment being compared to a new one or a placebo group which is not getting the treatment under evaluation but neither the patient nor their doctor will know. Anyone who breaches the randomization process risks the whole trial becoming wasted because statistical analysis may not provide the correct answer. All of this seems logical and wise, does it not? We all want treatment options that inform us of the true risk versus benefits, that have been established by "Grade A" scientific evaluation. Yet, if Dr. Sackett and his colleagues had not made this concept the fundamental center of their practice of health care, we may not have the universally accepted concept of Evidence-Based Medicine that we have in 2019. Dr. Gordon Guyatt, also at McMasters, was one of Dr. Sackett's trainees and he came up with the term we use today "Evidence-Based Medicine".

I was inspired to write this blog posting today because it is that time of year again when I do a summer vision science presentation to our new undergraduate and graduate research students on doing good science. The necessity of scientific practice for research and the evaluation of medical treatments, including new drugs, and the bad things that result when "Grade A" evaluations are not done or even when unethical practices put profits before patient welfare. An example of the later is apparent this week in our US news, as over 40 State AGs have launched class action lawsuits against most of the generic drug manufacturers who have been increasing the costs of otherwise old drugs by over 9,000 % in some cases. Clear evidence of drug company communications fixing pricing have been mapped out in great detail and we may be on the cusp of uncovering the largest antitrust event in US history in terms of costs. Over 85% of US drug prescriptions are for generic drugs and these prescriptions are the largest single driver of health insurance premium increases over the last 20 years. The millions of Americans that have been potentially harmed by this practice is shocking.

For physicians, Dr. Sackett wrote one of his group's articles in 1981 for the purpose of teaching medical doctors how they should read and evaluate the medical literature to determine what Grade of evidence is available to them at any time.

"How to read clinical journals: I. why to read them and how to start reading them critically." David Sackett, MD,
1981, in the Canadian Medical Association Journal.

You can get your very own free copy here, courtesy of Pub Med Central. If you are an old or new scientist or medical doctor, get it. It is four pages and one of the best-written papers you will keep among your most valuable favorites. It is also a very enjoyable read:

Dr. Sackett is certainly respectful and a gentleman scholar, but his note of Ernest Hemmingway's reference to "crap detector" tells me he was a guy I would have loved to chat with about science and medicine.

For more information on the current generic-drug lawsuits this week from US States AGs, I recommend watching the following story by CBS's 60 Minutes. It will make you quite angry, and well you should be if you take any prescription medications, including insulin:

As always,
you can be your own scientist and think.

Ken Mitton

I leave you with this quote as well, who could possibly resist. Not I.

"To invent out of knowledge means to produce inventions that are true. Every man should have a built-in automatic crap detector operating inside him." Ernest Hemmingway

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