Last weekend, my teenage daughter wanted to go to an event with some of her friends. I said no. If you have ever met a teenager, you know what her automatic response was.

“Why?”

The truth is I couldn’t tell her why. My gut simply said that it was a bad idea. The event itself wasn’t a problem; her friends are certainly not a problem. But something about the whole scenario made me uncomfortable. I did my best to explain without resorting to, “Because I said so.”

My explanation did not satisfy her.

But that’s okay. In parenting sometimes the best evidence we have to go on is our gut instinct. Every day we make decisions of every scale with limited information. Parenting, for all the books that would tell us otherwise, is often a fly by the seat of your pants proposition.

Not so with medicine. The practice of medicine, at its best, is based on evidence. A physician takes an oath that states “first do no harm.” Treatments that can potentially harm a patient must have some evidence to suggest that the benefits will outweigh that risk.

But that’s not always the way it goes, according to an article published in last month’s Journal of the American Medical Association. It suggests that some physicians are handling their prescription of treatment like I handled Friday night’s event with my daughter.

The study reviewed 40 encounters between cardiologists and their patients with coronary artery disease. It analyzed the way the physician presented the benefits and risks of percutaneous coronary interventions (for example, balloon angiography). In an alarming number of these discussions the evidence for the use of the procedure was not presented to the patients. In several encounters the risks were understated and the benefits overstated.

We can speculate on the reasons - financial benefit to the physician, familiarity and comfort with a certain course of treatment, a desire to put the patient at ease. Many factors are likely at play here.

But the reason the physicians presented the information the way they did isn’t the important point here. It’s the fact that they did present it that way. It’s the fact that doctors don’t always explain the evidence for the treatment they are recommending. So what do you do with this information?

 You’ve got to tap into your inner teenager. You’ve got to ask, “Why?”

“Why are you recommending this treatment?”

“Why do you believe it’s better than some alternative treatment?”

“Why wouldn’t I choose a less risky approach?”

And, like my daughter, you shouldn’t be satisfied with an unconvincing explanation. Your doctor should be able to explain that he recommends a course of treatment because it offers the best chance of improving your symptoms, prolonging your life, or some other benefit based on medical research. He should tell you about the likely downside of the treatment - again based on the research.

Sometimes the research is unclear, and he should be able to explain that to you as well. He might say that the research doesn’t show an advantage for one treatment approach over another. Then he should clearly explain the risks of each approach.

And since you aren’t a teenager anymore, you need to make the final decision about how to proceed.