Common Sense Is Not So Common.
— Voltaire (Francois Marie Arouet, 1694-1778), Dictionnaire Philosophique, 1764
This editorial is the second time I have discussed clinical aphorisms that have proved useful for me during more than 30 years of inpatient and outpatient attending at 4 US medical schools. The last time I put this list of aphorisms together, it contained 10 items. The current commentary will be published sequentially in 2 parts with 8 aphorisms in part I and 7 additional items in part II for a total of 15.
Rule 1: Common things occur commonly. I make this point continuously to medical students and residents. Sometimes young clinicians will suggest an unusual diagnosis for a patient with the hope of being the only doctor to make the correct diagnosis. More experienced clinicians believe the correct diagnosis is usually something common. For example, consider a patient with an enlarged spleen. In North America, splenomegaly rarely results from entities such as primary lymphoma of the spleen or malaria. Rather, splenomegaly is often caused by portal hypertension or mononucleosis. One of my first, and best, residents during my internship told me “If it looks like a horse, whinnies like a horse, and smells like a horse, don’t expect a zebra to appear” (Stone N, MD, personal communication, 1970).
The experienced clinician is aware of the relative incidence of various illnesses in his/her community, and, unless there are unusual features in a particular patient’s clinical picture, one should always seek one of the diagnoses most common in the community where one practices. For example, on moving to Arizona, I was amazed to discover how common coccidiomycosis pneumonia was in our hospital population. I had learned about this illness while studying and working in Boston. However, I had never seen an example of this disease entity and thought that it was a rarity. This is definitely not the case in Arizona where coccidiomycosis pneumonitis is common and should always be considered in the differential diagnosis of a pulmonary infiltrate.
Rule 2: Common sense occurs uncommonly. This aphorism is usually attributed to Voltaire. Over the years, I have seen many violations of this important rule in clinical medicine. Physicians should exercise common sense before ordering tests or performing therapeutic interventions. Examples abound in support of this rule. Recently, I saw a 60-year-old diabetic woman in my office. She had been admitted to our hospital several weeks earlier with a single bout of rest angina. Her cardiac catheterization revealed modest coronary arterial stenoses, and she was placed on medical therapy with brand name medications by another cardiologist: a statin, an angiotensin receptor blocker, and clopidogrel. Subsequently, I first saw her in my office. At that time, she and her family told me that they had paid more than $500 for 1 month’s supply of the medicines that had been prescribed in the hospital. I quickly altered her regimen to include generic forms of a statin and an angiotensin-converting enzyme inhibitor, as well as 325 mg of aspirin. These new generic prescriptions would cost the patient less than $20 per month. Common sense should have been used earlier by the inpatient attending physician simply by informing the patient that generic brands cost less than brand name pharmaceuticals. As noted by Harvey Cushing (1869-1939), “Three-fifths of the practice of medicine depends on common sense, knowledge of people and of human reactions.” I would add knowledge of the patient’s ability to pay for the medicines prescribed.
Rule 3: The less a procedure is indicated the more likely that its use will be accompanied by complications. This rule advises clinicians to ensure that every procedure or test ordered has a reasonable probability of altering patient management. An example of this aphorism in practice involved a healthy 55-year-old man without coronary heart disease risk factors. He became anxious when a neighbor had an acute myocardial infarction. His doctor suggested that he undergo a coronary calcium computed tomography scan. This test revealed modest coronary calcifications. The patient became more anxious when he heard the results of his computed tomography scan, and he convinced his physician that he needed a coronary angiogram. The angiogram was unremarkable, but the catheterization resulted in a large groin hematoma and pseudoaneurysm that required vascular surgical repair. If I had been involved in this patient’s initial care, reassurance or, at most, a Bruce protocol electrocardiographically monitored exercise test, would have been my approach.
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— Joseph S. Alpert, MD
This article was originally published in the August 2009 issue of The American Journal of Medicine.
