Thursday, August 7, 2014

Cutting through the noise



We have covered what a differential diagnosis is in a previous blogpostThe process of going through this differential diagnosis allows the doctor to uncover the potential causes of a patient’s symptoms, allowing them to devise the appropriate treatment plan for optimum recovery. 

This can be thought as the doctor attempting to uncover the primary signal (whatever the problem is, represented by the red line in the diagrams below). This process involves the physician going through a structured "interview", where they will ask the patient questions regarding their symptoms. Physicians have, through many years of education and experience, learned what questions to ask to get the needed information. 

Often patients will respond to these questions by giving very detailed responses in the hopes that the doctor will be able to pick out the hidden piece of information that will “break the case”. While in theory this may seem reasonable, in reality this information can be actually lead to confusion. Instead of providing additional clarity, it clouds the picture even more (like in the bottom diagram), making it more difficult for the doctor to locate the underlying signal. 

This is a concept covered by Nate Silver in great detail in his book Signal and the Noise. Each question is thoughtfully and deliberately chosen as a means of ruling in or out various diagnoses. The more succinct a patients answer, the easier it is for the doctor to cut through the noise and hone in on the correct diagnosis, and ultimately help the patient meet their goals!