Milton Packer explores whether theory helps or hinders decision-making My career in cardiovascular medicine had two distinct phases, both dedicated to improving the lives of patients with heart failure. The first phase focused on trying to understand the mechanisms of the disease: how it evolves and what systems are responsible. The second phase focused on developing and testing new treatments for heart failure, in order to reduce symptoms and prevent hospitalizations and death. Most of what I had learned about the biology and physiology of heart failure in medical school turned out to be wrong, and it was wonderful to discover new ways of thinking about the disease. But knowledge of these new pathways would not benefit patients, unless it could be translated into new treatments. An effective new treatment would improve the lives of millions of people. And at the same time, it would prove that our new thinking about mechanisms was actually correct. There is a nonseverable link between understanding a disease and treating it, and also between treating a disease and understanding it. This interconnectedness is the basis of how physicians learn medicine. In medical school, students learn biology and pathophysiology to understand the phenomena that they will subsequently observe in patients. This understanding drives their ability to use treatments wisely and recognize their adverse effects. But some wonder whether all of the links between the theory and practice of medicine are really necessary. Perhaps they are a luxury that society can no longer afford. Look at the typical medical school curriculum. It's filled with courses in biochemistry, molecular biology, genetics, neurosciences and other basic science disciplines. For many, this knowledge is a source of wonderment. But admittedly, students routinely memorize thousands of facts that they will never put into practice. Look at clinical practice. Physicians spend more time on administrative details and struggling with third-party payers than thinking about disease mechanisms. Furthermore, a physician who understands mechanisms but has horrific interpersonal skills cannot deliver quality care. So why not reinvent our healthcare delivery so that it emphasizes the role of non-physician healthcare practitioners who can prescribe the right treatments in a compassionate manner without a detailed background and knowledge about how the body actually works? You can even make a persuasive case that requiring an understanding of a disease or the mechanism of action of a drug is a hindrance. Here are four intriguing examples. First, most of our predictions about which new drugs are likely to work and which are likely to fail -- based on theories -- prove to be wrong. I have been closely involved in nearly 30 clinical trials of new interventions in heart failure, and most showed that the proposed new treatment did not work or was harmful. Understanding the theory did not reliably lead to new and useful therapies. Second, physicians often delay prescribing a newly approved drug until they can grasp its mechanism of action. A drug may have been demonstrated persuasively to reduce mortality dramatically in a dozen large-scale clinical trials. But many practitioners will delay using the drug for years until they are comfortable understanding how it works. If the mechanism is not attractive or does not make sense, the drug will not be prescribed. If this prolonged waiting period deprives patients of the benefits of new drugs, it might be better to assign the responsibility of treating patients to non-physician practitioners. Third, some would argue that drugs are so complicated that we really never know how they work. We can only guess, and our guesses keep changing. Digitalis was initially conceived as a diuretic, then as a positive inotropic drug, and most recently, as a neurohormonal antagonist. Sodium-glucose cotransporter-2 inhibitors were first developed to lower blood glucose, but they exert their most dramatic effects to prevent heart failure -- we do not know why. Perhaps they are acting as diuretics, maybe as metabolic agents, or conceivably as drugs that directly protect the heart. We know they work, but we do not know how. Fourth, if physicians are required to spend an enormous amount of time learning the theory of medicine, yet insurance companies drive the decision-making process, physicians might begin to resent all of the time they spent learning the theory of medicine. Does this contribute to physician burnout? For all of these reasons, some would argue that the theory and practice of medicine should be separated. Perhaps we should train a limited number of physicians who will devote their energies to the theory of medicine. At the same time, we should dramatically increase our training of non-physicians who will be primarily responsible for the implementation of established standards. This proposal has merits, but its advocates ignore how medicine is practiced and how it advances. When I was a freshman in medical school, I was told that 50% of what I would be taught for the next four years would be subsequently proven to be invalid. So we attended classes knowing that we needed to make a life-long effort to keep checking the validity and updating the usefulness of our information. The only way to do that was through medical practice. It is the experience gained in medical practice that is the primary driver of changes in medical theory. Nearly every new treatment for heart failure was developed based on observations at the bedside and not in the basic science laboratory. It is true that laboratory observations have led to incredible progress in the treatment of cancer, but that research was driven entirely by experience in human beings. New drugs and devices are developed based on theory, but those theories are discarded when the treatments fail to deliver in practice. Most importantly, patients do not come to physicians with classical descriptions that are found in textbooks. They present with complicated stories, consisting of interwoven elements filled with incomplete and contradictory patterns, potentially representing one or many disorders. The truth can only be deciphered by someone with an understanding of the incredibly complex biology of human beings. Furthermore, most decision-making in medicine is not based on the findings of randomized clinical trials or even observational studies. It is based on our expectations of how the body works. Should we mass-produce healthcare professionals by minimizing their knowledge of theory and maximizing their compliance with standardized algorithms? When I see a physician for a medical problem, I am not looking for someone who will be satisfied with checking boxes that some society or insurer has created. I am seeking a thoughtful and compassionate professional who will discover what is going on and will treat my illness on an individual basis. The theory of medicine is critical to the delivery of personalized and effective care. An understanding of disease mechanisms may be burdensome and may often be wrong. But separating theory from practice means relegating both patients and physicians to the status of a commodity. And we deserve better than that. Source
