How doctors think
Part 1 of 2
I thought I knew it well
Before I ventured into politics, I practised medicine for a little over a quarter of a century – first as a general practitioner, then as a pediatrician and later as a heart and lung specialist, medical teacher, writer and lecturer. Hence, I thought I knew very well how a doctor’s mind works in arriving at a diagnosis and prescribing the appropriate treatment, at least in children. Not until two years ago this past Christmas when our son Sherwin and his friend, now his wife, Trish gave me as a present, the paperback, How Doctors Think. Authored by Dr. Jerome Groopman, Professor and Chair of Medicine at the Harvard Medical School, the book shines light on how a doctor’s mind – if closed, biased, uncritical and stereotyping – can easily be led astray into making a wrong diagnosis and how patients and their loved ones can alert their doctors to open their minds and think better. I have read it much more than once and I continue to learn every time my eyes moved through its pages.
A doctor’s mind inspires a book
The book makes fascinating reading both for how it came to be conceived and for its twin messages to patients and physicians. The doctor-author’s own account of its conception, gestation and birth reflects attributes that patients would like to see in their attending physicians. It also reflects what physicians would like to see among their peers – keen powers of observation, critical thinking, humility and openness of mind, perseverance and patience through completion of a task, compassion, a thirst for new knowledge, a sense of duty to one’s calling and an appreciative understanding of the profession’s reason for being.
The seed for the book began to germinate after several teaching rounds the author had had with his medical students, interns and residents. He marvelled at their adeptness in citing statistical numbers and using the pre-set decision-tree guidelines called clinical algorithms in making a diagnosis. Nonetheless, he worried. He detected in his trainees a lack of depth in analyzing the reasons for the patients’ hospitalization and an absence of meaningful dialogue with their peers and patients. He wondered how they would handle their future patients with complex signs and symptoms and unexplained test results. On further reflection, he realized that medical teachers seldom actually explain the mental steps to making a clinical diagnosis.
Eventually, he asked himself, “How should a doctor think?” The question itself raised many more to all of which his colleagues and the medical literature could only provide confessions of ignorance and an absence of realistic models for bedside teaching. While the non-answers he received helped explain his own limitations as a medical teacher, it only provided cold comfort. Far more important to him was his intuitive belief that “knowing his own way of medical thinking, particularly its pitfalls, would make him a better caregiver.” He reasoned that the frequency of diagnostic mistakes and their severity could be reduced by understanding how a doctor thinks and how a doctor can think better. Who could help the doctors think better? The search for answers led to the birth of this book
Three cardinal cognitive traps
The author’s journey of discovery brought him to attending a medical conference on medical errors where he not only narrated his own “painful experience” with misdiagnoses as a doctor and a patient but he also helped advance our understanding of the subject matter by providing the explanations based on the science of cognition. Other participants shared similar practice encounters. He has since classified the cognitive pitfalls physicians can make into three cardinal types:
- Anchoring error, that is, making a hasty diagnosis solely on the basis of the patient’s initial symptom and stopping to explore other diagnostic possibilities;
- Attribution error, that is, wrongly ascribing the patient’s persistent complaint or presenting symptom to a benign condition by stereotyping the patient negatively as a “known complainer” or positively as “all strong … with health and vigour,” and;
- Availability error, that is, wrongly assigning the patient’s complaint and symptoms to a certain specific diagnosis based simply on the ease with which the diagnosis comes to mind because of the commonness of that disease in one’s own clinical practice.
Thinking errors versus medical / technical mistakes
Even the most brilliant and highly skilled physicians and surgeons sometimes do not get it right. In fact, diagnostic errors have occurred in one of six or seven patients examined – a frequency of about 15%. Most of the errors, however, were neither medical mistakes (a result of inadequate medical knowledge or ignorance of clinical facts) nor technical mistakes (a result of mislabelling an x-ray film and incorrectly transcribing the dose of medications). Most errors were cognitive due to flaws in thinking as a result of bias, unwelcome attitude and the doctor’s absence of critical thinking.
While it is somewhat comforting that most errors are not medical or technical mistakes in nature, it should be emphasized that thinking errors have also resulted in serious harm. It is even more distressing to learn that most doctors are not aware of their cognitive mistakes. But thinking errors have not only led to misdiagnosis and harm but also to unnecessary and burdensome laboratory tests and treatment and, therefore, could lengthen patient waiting lists and create unnecessary health care costs.
The Honourable Dr. Rey D. Pagtakhan, is a retired lung specialist and University of Manitoba Professor of Pediatrics and Child Health. He is also a former Member of Parliament and senior cabinet minister. He is widely published and lectured in Medicine and Politics. He has been the recipient of several honours and awards, including the honorary Doctor of Science and Doctor of Laws, and is listed in the Canadian Who’s Who.