Mechanic

Most of you know how it works. You go to a mechanic for an oil change or a car problem. He changes the oil, or fixes the problem, and then he tells you "the timing belt is due for a change" or "you need a new battery."
Do you trust him? Do you have him do the work?
No. He has a financial incentive to do work on your car, regardless of whether the car needs that work done or not.
Three years ago, two different mechanics told me I needed a new battery, because my old one was near death. That old one still works fine, thank you.

Another scenario. You go to your doctor. He takes a look at your problem and recommends a surgery. What to you do?
You trust him. Your insurance pays thousands of dollars for the surgery.
And yet most doctors work much like mechanics--they get paid based on the number of surgeries they perform. And so they recommend way more surgeries than are actually necessary. This can actually do more harm to your body than good, as surgeries, and spending time in the hospital, always come with a bit of risk--a risk that is often bigger than the problem the doctor is solving with surgery.

So what do we do about it? Go to a hospital that doesn't pay doctors based on how many surgeries they do. A hospital that treats employees like most companies do--pays them a salary, expects 40 hours a week from them, and fires them if they cause too many problems or slack off. These doctors are more likely to have your interests at heart.
Unfortunately, your insurance is paying doctors to perform unnecessary surgeries on someone else. So you're paying doctors to perform unnecessary surgeries on someone else.
The system is broken. We need to stop paying doctors money based on the number of surgeries they perform, and start paying them for how well they help people become healthy.