Science

My mentor speaks of medicine's interest in the similarity and difference between individual patients. With huge variation from person to person, it is never possible to consider medicine in the same scientific way as Newtonian physics. To paraphrase the old saying, medicine is knowledge, judgment, experience, and luck.

It is ironic that as we are getting a better picture of how epidemiology studies get closer to predicting illness (or recovery from an illness), we are learning at the same time to realize how irrelevant the scientific statistics can apply to a single individual patient who is sitting in front of a medical doctor. Despite evidence based medicine's miracles like the oft-quoted p values or gene-expression signatures of human diseases – and they are touted as the elixir to make you a crystal ball – clinical knowing for the individual patient in acute care is not certain, nor will it ever be.

In the midst of cudgeling your computer and googling the chance of having a heart attack, you will soon stumble on the illusion how precise the prediction rule can be. These prediction rules might fare well in a population, but seldom work wonder for an individual patient. In the past few decades, for example, medical journals have published a flurry of scientific papers on the link between tobacco and heart attacks. But in case your patient complains of sudden chest pain, dare you forget about doing a workup for myocardial infarction because he doesn't smoke?

I dare not.