In this interesting article by Charles Ornstein, he explores the concept of why having too many tests done to your body when you are healthy could actually have a detrimental effect due to increasing the chances of a false positive, coupled with the fact that our bodies are constantly changing and that an abnormal result may be perfectly fine.
Those of us who program and perform analytics are frequently the type of people who like consistency. 1 + 1 = 2. Not all fields are so cut and dried though, human-beings falling into that category.
So as we dive deeper into healthcare data analytics, we are melding the two worlds of 1+1=2, along with inconsistent variability, which can make for challenging predictions.