Decision making under conditions of uncertainty

I graduated from medical school 29.5 years ago. To this day medicine fascinates me. I have often reflected on the reasons for my continued attraction to my profession. In so reflecting, I believe that I understand an important philosophical underpinning that many non-physicians do not understand. If I am wrong, please forgive my arrogance.

Physicians make many decisions each day. We explore diagnostic dilemmas; we prescribe medications; we order tests (and interpret those tests); we operate. Each of those acts occurs with uncertain knowledge. We rarely are 100% certain in medicine, rather we must make probabilistic decisions.

A few examples might clarify my thinking.

A 30 year old man discovers that he has elevated blood pressure. He comes to your office. What decisions must you make? First, because of his age you must consider the possibility that he has a secondary cause for his hypertension. You must decide whether to spend moneys ordering diagnostic tests for those causes. You will probably pick a medication to lower his blood pressure – a decision which has fuzzy borders. You will develop a goal blood pressure. You must consider what other problems he might have – e.g., prediabetes, increased cholesterol, early heart disease. You assess his risk factors for other disease – smoking, alcohol, illegal drugs, unsafe sex. This list is not complete. Yet for this most simple of complaints, you must make many decisions. And the decisions are not automatic, algorithmic, or necessarily easy.

A new drug enters the market. The “hype” defines its position in our armamentarium. But as a long time physician you have a healthy fear of new drugs. Too often you have seen problems arise after 5 years. How do you decide whether to prescribe the new wonder drug?

A 55 year old woman presents for a routine physical. She asks for a chest X-ray so that she can work at a nursing home. The CXR shows a coin lesion. What do you do?

This last case haunts me. I had such a patient as a resident. We referred her to surgery for removal of a suspicious coin lesion (that was clearly the standard of care in 1977). The coin lesion was benign. Six days later she died of a pulmonary thromboembolus.

As physicians we rarely know answers definitively. We make our best probabilistic guesses, and then hope for the best. But given the uncertainty, we have results that we question in retrospect.

I doubt that we will ever rid medicine of that uncertainty. The uncertainty attracts me. The quest to make the best decisions (while never really knowing that we did) is a quest worth taking.

We take our quest seriously and hope that we do much more good than not. But some patients will have bad outcomes; some patients will die; and we will make some mistakes. We learn to live with uncertainty and hopefully thrive under these conditions. But it is important that patients understand that we are not always certain. It is important to understand that even when we make the “right” decision, the patient may not do well.