August 17th, 2011
How Cardiologists Think
Today on CardioExchange, we launch a new mini-series of blog posts on decision making in cardiology. Dr. John E. Brush explores the conscious and unconscious mental strategies that cardiologists use in their everyday work and asks you to examine your own decision-making processes. The aim: to foster a rich dialogue about how we do what we do so that we ultimately improve the care of patients.
A 60-year-old man with systolic heart failure is admitted to the hospital for shortness of breath. You are making rounds when the nurse calls out that the man has collapsed in his room. You look at the telemetry monitor at the nursing station and immediately recognize that the patient is in ventricular tachycardia. After you shock the patient, normal sinus rhythm is restored and the patient recovers.
Another patient comes to the emergency room with chest pain. An urgently performed electrocardiogram shows ST-segment elevation in 3 leads. Without further questioning, the cardiac catheterization laboratory team and the interventional cardiologist are called in for an emergency procedure.
A third patient is admitted with unexplained fever and night sweats. She has new diastolic murmur on exam but also has some enlarged lymph nodes and a 1-week history of diarrhea. After a thorough evaluation and a careful weighing of the evidence, the patient is ultimately diagnosed with subacute bacterial endocarditis.
As these examples demonstrate, cardiology is a field that employs a variety of decision-making strategies. Some tasks demand instantaneous decisions; others require a more deliberative, logical approach. And many of our daily medical decisions are “best guesses” because of the uncertainty surrounding complex diagnostic dilemmas or therapeutic decisions that aren’t directly guided by a basic scientific principle or data from a clinical trial. For the rapid decisions, we frequently use mental shortcuts called heuristics. For the complicated but routine daily decisions, we often use intuition, inductive reasoning, and inference.
How doctors think is fascinating, yet the field of medical reasoning seems to be either ignored or assumed in medical education and practice. In my opinion, because there is enormous variation in how we all make medical decisions, many of those decisions may be suboptimal. Placing greater emphasis on medical decision making in medical education and research represents a big opportunity to improve the quality of medical care.
To examine medical decision making, one must start by evaluating the role of intuition. Whether using intuition is good or bad and whether we should allow our rational mind or our intuition to dominate our thinking has been a source of debate since the days of Plato and Aristotle. The debate raged through the era of the Enlightenment between Descartes and Hume, and through every age and generation since. In recent decades, the fields of cognitive psychology, behavioral economics, and evolutionary psychology have revealed insights into the structure of decision making and have renewed interest in the role of intuition and the value of heuristics. Many popular books such as Blink by Malcolm Gladwell and How We Decide by Jonah Lehrer have brought the research findings about intuition to a larger audience.
The wisdom of the ancient philosophers and the research findings of modern psychologists elucidate the complexities of human cognition in ways that could greatly improve the quality and consistency of medical decision making. As the educator and pragmatic philosopher John Dewey wrote in his book titled How We Think, “The aim of education should be to teach us rather how to think, than what to think — rather to improve our minds, so as to enable us to think for ourselves, than to load the memory with the thoughts of other men.”
Three recent books have raised awareness specifically about medical decision making. Jerome Groopman attracted much media attention with How Doctors Think, where he exposed the use of heuristics in medicine. The fact that we frequently use these cognitive shortcuts was news to much of the lay public, who may have assumed that medical decisions are exactly and precisely defined by rigorous science. In another book also titled How Doctors Think, Kathryn Montgomery posits that medicine is not a science, like Newtonian physics, but is rather a practice, where custom and routines enable doctors to think through the uncertain decisions that are part of their everyday work. She emphasized how doctors use narrative to construct a mental picture and employ abductive or retroductive reasoning to make clinical diagnoses. In Learning Clinical Reasoning, Jerome Kassirer and his coauthors offer numerous examples of the variety of thinking styles that doctors use, as well as the many fallacies and the biased reasoning that can often come into play in medical practice.
In designing a typical medical education curriculum, we tend to focus on the content of medicine: what is known and what is new. We often deny the fact that much is unknown and that many decisions are made under conditions of uncertainty. No common curriculum prepares physicians for the uncertainty of practice, and few courses explicitly teach the mental processes that help us cope with uncertainty. Greater focus on medical reasoning strategies in both primary and continuing medical education would help create a common vocabulary and structure that could improve those strategies and enhance consistency. In addition, greater emphasis on medical reasoning in real-world clinical practice could yield new opportunities for research that uncovers the components of good decisions and allows us to disseminate the best practices.
I started this commentary with three examples of decision making from cardiology practice. The first makes use of the recognition heuristic. The second uses a “take the best answer” heuristic. And the final example synthesizes a variety of cognitive processes, with the ultimate decision likely resulting from the use of either the anchoring and adjusting or the tallying heuristic. In the next several blog posts, I will expound further on these and other medical decision-making strategies.
As this series on decision making in cardiology progresses, I ask you, as CardioExchange members, to engage in dialogue — both with me and with one another — about this important topic. My hope is that together we will become more aware of our decision-making processes and ultimately use that understanding to improve practice. Please join the conversation.