ERRORS IN MEDICAL DIAGNOSIS AND FLAWS IN HUMAN JUDGMENT
“A physician’s forecast of disease by patient’s pulse and purse.” - Ambrose Bierce (1842 – 1914)
I am sure that most of us have encountered the fact that different doctors, even in the same city, give us different diagnosis for our medical problems. Since we are the same patient with the same complaints, with the same physical and lab findings, then why are we given different diagnosis by different doctors? Obviously, the cause is the doctors themselves.
Maybe if we look at the doctors’ diagnostic decision-making process more closely, we can ascertain the cause. Medical diagnosis always requires some kind of judgment. Judgements are physically and psychologically subjective and very personal.
I vividly remember during my gastroenterology training my teacher and mentor, the renowned professor Dr. Eddy Palmer saying, “there are two types of doctors when they see a patient, one thinks how can I help the patient? This is a real and dedicated doctor. The other one thinks how much money can I make out of this patient? This is a corrupt, businessman doctor. I want you to become, and I would train you to be a real dedicated, and good doctor.”
Even though most doctors are honest and honorable people, I believe that some doctors are prone to take their self – interest before the patient’s interest, by advocating a diagnosis that require more testing, more procedures, more intervention, including surgery, in order to make more money. Therefore, in non-urgent situations, if any patient encounters a diagnosis that makes no sense and not acceptable to them, they should always seek a second opinion from a reputable doctor before making a final decision about their diagnosis and their medical care.
No doubt that there are many other reasons for errors in medical diagnosis. Among them are lack of medical knowledge, poor training, lack of experience, incompetence, having limited diagnostic abilities, not to keeping-up with current medical knowledge could be easily stated.
As assured, these are not the only reasons for errors in medical diagnosis. Believe it or not, the most common reason for medical errors is the existence of universal and general flaws in human judgement. Flaws in human judgement causes errors not only in medicine, but also in all other professions; in short, in every sphere of human endeavor.
A recently published exceptional book on this important subject, written by three great thinkers: Kahneman, Sibony and Sunstein, entitled “Noise.” In this book, they convincingly explain why there is so much variability and flaws in human judgements, how to reduce decisional errors, how to re-think to make right decisions, solve problems, and evaluate other people for hiring.
I shall try to summarize my take and my understanding of this book, as I see it. But I strongly advise interested readers to read and study this exceptional book.
Noise, in the book is defined as “variability in human judgement”, and it’s usually caused by subjective cognitive bias, which we all possess. Bias and noise are different components of errors in human judgements. Then, to understand errors in human judgement, we must first understand the bias and noise, be aware of them and overcome them, so that we can improve the quality of our judgement.
Judgement is not synonym of thinking, it’s more a form of subjective decision making that refers to the measurement of the circumstances of that moment and the mental state (angry, depressed, happy, moody) of the decision maker. Judgement, therefore, can be described as a measurement of an event or issue by the human mind. The human mind, on the other hand, isn’t a perfect measurement instrument; it is both biased and noisy.
That is how humans are genetically created. Variability in human mind is psychologically given, and it is subjective and biased. Judgement is like prediction. One can never be certain that a judgement is error free and correct. That is why we often hear the phrase “It’s a judgement call” or “a matter of judgement.” In matter of judgement, unlike opinions, it’s understood that in judgement, unresolved differences are acceptable.
Bias and prejudices are so rampant in the human mind that we might not be even aware of all of them. In addition, we often tend to form impression quickly and hold on to them even when contracting information comes in. There are three types of biases that operate in different ways:
1. Substitution Biases which leads to misvalue the evidence.
2. Conclusion Biases which leads us to bypass the evidence or to consider it in a distorted way.
3. Excessive Coherence Biases which magnifies the effect of initial impression.
All biases produce noise in human judgement. Consider a physically attractive, beautiful or handsome candidate whose good looks creates an early positive impression. But if physical appearance is irrelevant to the position, this biased impression will result in error in decision making judgement.
When the amount of noise is too much, or the data to review is massive, then it is worth replacing human judgment with rules and regulation, or algorithms or AI machines’ decisions.
I personally believe, we often treasure variability in artistic taste, political view or picking friends. Uniqueness of people makes them capable of innovation and creativity, and simply interesting and exciting to be around. AI machines should never be allowed to replace human judgement, because AI machines have no soul, no feelings, no empathy, no humanity in them. They should just be secondary helpers to human judgement.
